Not sure if this is okay to share but in the interests of keeping everyone in this loop up to date...
Update: My Dropbox context menus are back. This solution works. Fingers crossed it stays that way!!
I have been exchanging emails with a very helpful Dropbox engineer and he has stepped me through a few options. Most didn't work. This latest one does, but it's a step back to a previous stable version of the app.
I was told that Dropbox are working on an updated version of the app that will bring back the context menus as they are aware of the problem. However, this may take a week or more. In the meantime, he suggested I roll back to an older version of the app that still works with the context menus on the latest version of Windows 11. You can find the download link to the install file here: https://www.dropbox.com/downloading?build=158.4.4564&plat=win&type=full&arch=x64
Now, a few things to note:
1. You do not need to uninstall the existing app. Just click and install this older version on top of it. It will override the existing version.
2. Give it time. It takes a bit after the install to click online. Check that the older version of the app has "taken" by hovering over the Dropbox app icon and checking the app version. It should be 158.4.4564.
3. After the install is finished, Dropbox will sync and will re-index all your local files on your hard drive in the Dropbox folder. That will take a while, depending on how many files you have and how big the total storage space is. Be patient.
4. Your context menus will slowly come back online in Windows Explorer when you right-click as each file and folder finishes syncing and indexing. If you right-click and the Dropbox context menu isn't showing, it probably means it is still syncing and indexing. Again, be patient. Once that's finished, your context menus should be back for all your files and folders in Dropbox.
5. VERY IMPORTANT. You need to DISABLE the auto-update for Dropbox until the new stable version is installed (when it eventually comes out) and you stay on this version. 158.4.4564. To do that: open Task Manager (CTRL+ALT+DEL) and go to the PROCESSES tab. Scroll down to BACKGROUND PROCESSES and keep scrolling until you get to "Dropbox Update Service (32 bit)" and click on that to highlight it. Then right-click and select "End task." That will disable the auto-update TEMPORARILY.
NOTE: if you reboot your computer, the Dropbox auto-update task will enable again, so each time you reboot, you will need to disable the auto-update process. Just repeat STEP 5. There is no real way to turn it off permanently, and there's a whole Dropbox thread about it. If you want to read about it, it's here. https://www.dropboxforum.com/t5/Apps-and-Installations/How-to-disable-DropBox-Update/td-p/199292 I wouldn't recommend it anyway because you do actually want the auto update to work, and it's part of Dropbox's policy. I wouldn't mess with it anymore permanently. If you are in contact with a Dropbox engineer via email as part of this issue, they will be able to turn it off for you on their end, but you have to ask.
Good luck.
Shout out to the Dropbox engineer helping me. He was super helpful and very responsive.
