Just for "fun", I will paste here the answer that a "dropbox support employee" gave me via their official support. this is only PART one as the answer was SO LENGTHY that it passes our serer's 10k character limit:

(please, don't waste your time reading it all - I didn't and told them I wouldn't read an AI-generated answer)

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"Hey El,

Appreciate the context.

I've been digging around for the last hour regarding this anomaly. Users on Zorin OS 18 (based on Ubuntu) have reported that the Dropbox application’s system tray icon appears but does nothing when clicked – the expected menu (for preferences, recent files, etc.) does not open. This issue is not unique to Zorin; it has been observed on Ubuntu 23.04, 23.10, 24.04 LTS and even other distros like Fedora 38, particularly those using the GNOME desktop environment. In other words, the Dropbox icon is visible in the panel, and it updates (showing syncing status or a checkmark), but clicking it yields no dropdown menu. This is a known bug with the Dropbox Linux client’s tray/AppIndicator integration on recent Linux desktop environments, and it is not caused by user error or a Zorin-specific configuration.

A Workaround I've found, the Lock/Unlock Trick: An interesting but consistently reliable workaround, locking the screen and then unlocking it causes the Dropbox tray menu to start working normally. After performing a screen lock (for example, pressing Super+L or using the lock option) and then logging back in, the previously unresponsive icon suddenly responds to clicks and shows the menu as expected. Many users have confirmed this odd workaround across different systems, and it suggests the issue may relate to how the desktop initialises the tray icon or window focus on login. While effective, this workaround is obviously inconvenient to perform on every login.

Cause and Context: The root cause appears to be an incompatibility or bug in how the Dropbox client registers its tray icon menu with GNOME’s AppIndicator system (which replaces the old system tray in modern Ubuntu/Zorin). GNOME requires a special extension (“AppIndicator and KStatusNotifierItem Support”) to display tray icons for apps like Dropbox. If this extension is not installed or enabled, Dropbox’s icon/menu will not function properly. In Zorin OS (and Ubuntu), this extension is usually enabled by default so the icon does show up; however, even with AppIndicator enabled, the Dropbox menu fails to open until after a lock-cycle – indicating a bug either in the Dropbox client’s AppIndicator implementation or in GNOME’s handling of it. Some have noted that certain GNOME Shell extensions (for example, “Dash to Panel” which modifies the panel) might exacerbate the issue, but even with such extensions, the lock/unlock method restores the menu functionality. The problem occurs on both X11 and Wayland sessions of GNOME, so it’s not strictly a Wayland issue. It has been logged in Ubuntu’s bug tracker (nautilus-dropbox package) and remains unfixed as of Ubuntu 24.04 with the latest Dropbox versions.

Possible Solutions:
Use the Lock/Unlock workaround when needed: This is the simplest immediate fix – if you click the Dropbox icon and get no response, press Super+L to lock the screen, then log back in. The Dropbox menu should then drop down normally. This does not require any installation and can be done on the fly, but you have to repeat it after each reboot or Dropbox restart.
Ensure AppIndicator support is installed: Verify that the “AppIndicator and KStatusNotifierItem Support” extension is enabled on your system (on Ubuntu/Zorin you can check GNOME Extensions or ensure the package gnome-shell-extension-appindicator is installed). In most cases it already is, otherwise the icon wouldn’t show at all – but it’s worth confirming, because without it, the Dropbox icon menu cannot display in GNOME at all.
Avoid conflicting extensions: If you have GNOME extensions like Dash-to-Panel or others that modify the system tray/panel, try disabling them to see if Dropbox’s icon behaves better. Users have reported that even with Dash-to-Panel, the lock/unlock trick still works, but in some cases an extension might interfere with the tray. Using the default panel (with the AppIndicator extension) is the configuration Dropbox is most tested with.
Automate the fix with a startup script: To save from manually locking the screen every time, some advanced users have created a startup script that toggles the AppIndicator extension off and on shortly after login. This essentially simulates the effect of a lock cycle. For example, a script can run: gnome-extensions disable ubuntu-appindicators@ubuntu.com; sleep 2; gnome-extensions enable ubuntu-appindicators@ubuntu.com a few seconds after login. This forces the panel to reinitialise the indicator icons, and users report Dropbox’s menu then works without manual intervention. After adding such script to Startup Applications, the fix is applied automatically on each login.
Wait for an official fix: Ultimately, this is a bug in our Linux client (or its integration with desktop environments) that my development team needs to address. The issue has been widely reported, and our forums thread and the Launchpad bug have multiple pages of confirmations. For now, employing the above workarounds is the way to manage it. If you’re comfortable, you might also update to the latest Dropbox beta to see if the issue is resolved, and follow our release notes for any mention of tray icon fixes.

Dropbox Folder on NTFS Drive – “Unsupported File System” Error on Linux

Dropbox client showing the “Unsupported File System” error when attempting to move the Dropbox folder to an NTFS-formatted drive on Linux. The message states that to sync, you must use a “compatible” file system, and that Dropbox is compatible with Ext4 on Linux.

The second issue is that we will not allow a user to set an NTFS-partitioned drive as the location for the Dropbox folder on Linux. In the scenario described, when a user tried to choose a folder on an NTFS drive (mounted in Zorin OS) as the Dropbox sync folder, the application produced an error dialog saying: “Unsupported File System – To sync your Dropbox, move your Dropbox folder to a partition with a compatible File System. Dropbox is compatible with Ext4.” This is an intentional limitation of the Dropbox desktop app on Linux, not a simple bug. In fact, Dropbox has explicit filesystem requirements on each OS:

Windows: Only NTFS-formatted drives are supported for the Dropbox folder. (NTFS is the standard Windows filesystem.)
macOS: Only HFS+ or APFS volumes are supported (the typical Mac filesystems).
Linux: Only certain Linux-native filesystems (ext4, and a few others) are supported – NTFS is not supported on Linux forums.opensuse.org

We made this policy change in late 2018, when they announced that Linux Dropbox would only sync to drives using ext4 by default. The official reason given was that Dropbox “relies on extended attributes (X-attrs) to identify files in the Dropbox folder and keep them in sync”, and we would therefore support only the most common filesystem types that fully support these extended attributes. At that time, ext4 was mandated (and many less common Linux filesystems or any encrypted filesystems were flagged as “unsupported”). In practical terms, an NTFS partition mounted on Linux via the ntfs-3g driver was deemed an “uncommon filesystem” in this context and disallowed. Even though NTFS does support extended attributes on Windows, the Linux implementation of NTFS may not support all the features or consistency Dropbox expects. The Dropbox app detects the filesystem type of the chosen folder, and if it’s not in the approved list, it will refuse to use it – hence the error you've encountered.

Current Supported Filesystems on Linux: Over time, Dropbox broadened support slightly beyond just ext4. According to our official help center, the Dropbox folder can reside on an ext4 filesystem, or on other Linux filesystems that support xattrs such as ZFS, XFS, Btrfs, or an eCryptFS encrypted home (which sits on ext4) help.dropbox.com. These are all native Linux filesystems known to work with Dropbox’s xattr requirements. Notably, NTFS is still not on the supported list for Linux. This means if you try to point Dropbox to a folder on an NTFS volume, it will consistently throw the “Unsupported File System” message. The fact that it works on Windows (where NTFS is native) does not carry over to Linux.

In your case, you have your data drive formatted as NTFS (perhaps for Windows compatibility in a dual-boot setup). While Zorin OS can mount and use NTFS drives for normal file storage, the Dropbox application will not accept an NTFS path for its syncing folder. The error you saw is exactly in line with Dropbox’s design – it’s informing you that on Linux the expected filesystem is ext4 (or another supported Linux FS). To resolve this, there are a few options or workarounds, albeit none as simple as just clicking “OK” on the error:
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