After vanilla installation of Ubuntu 22.04 LTS I have noticed 2 related issues with the icon in the systray.
For clarity, the client was installed from Ubuntu Software, following the usual methodologies for set up.
The first issue is that the icon is not persistent. After a while, the usual "stacked box" icon transforms in to a 3 horizontal dot icon. If left to it's own devices, after a while it returns as it should be but some time later it transforms again. There appears to be no detectable reason for this behaviour.
The second connected issue is that with either icon in place in the systray, selecting the icon with a mouse click (either left or right) the menu presented includes as normal the option to Launch Dropbox Website.
On my 20.04.4 LTS system, that works correctly in that it does indeed launch the home page of my Dropbox account but on 22.04 LTS it attempts to launch file://tmp/dbox/ followed by a long string of letters and numbers which Firefox errors with File not found.
The questions
In the case of the first issue (changing icon) is there a way of rendering the correct icon persistent?
In the case of the second, is there a way of editing the address to which the menu option refers?
The issue of the Dropbox drop down menu selecting the wrong web page has now been resolved by removing FF snap and installing the .deb version in its place using the instructions set out in this FOSTips article which specifically addresses Ubuntu 22.04 LTS:
https://fostips.com/ubuntu-21-10-two-firefox-remove-snap/
Following these instructions version 100.0 was installed (as at 10th May 2022).
A further advantage of the .deb version is that it also allowed the installation of the GNOME browser extensions avoiding this message which appears on the snap version.