Hello,
Could you contact me to my support e-mail?
Closing browser should not disable any add-ons, this may be related to something broken in your profile. Old profiles from before 57 era are often broken in some way and it's good to use Firefox Reset to fix all profile issues. Resetting profile will preserve your passwords, bookmarks and other important things (but not add-ons data).
Before resetting your profile I would suggest you to setup Firefox Sync. - this will backup the list of installed add-ons and after reset it will reinstall them.

Best regards,
Juraj Mäsiar

Hello,
Please contact me to my support e-mail if you need assistance with data recovery. There are ways to recover your data even without backup or cloud account.

Best regards,
Juraj Mäsiar

Hello,
If you need assistance with restoring your data, please contact me to my support e-mail. There are ways to restore your data even without backup or cloud.
Best regards,
Juraj Mäsiar

Hello,
Please contact me to my support email.
Also please send me add-on version and your Firefox version and a screenshot would be also helpful.
Also check Options page / Thumbnails / "Auto-reload target screen resolution" - it should be set to automatic.

Best regards,
Juraj Mäsiar

Hello,

The bookmarks synchronization will come eventually. But it will take some time... there is just too many things to do.
Regarding my cloud server - as I'm the only author, I can guarantee you, nobody except me has access to the cloud. That also means that I'm the weakest link in the chain - which means it's pretty strong chain :) as I'm a professional programmer with great skills regarding security.
But for the future I'm planning also end-to-end encryption to make things even more secure.

Regarding my income - this is very bad. I have almost none (as you can see in my Patreon page). I live from my savings from previous jobs.
But I do what I love and it's used by so many happy users (which is a great feeling!) so I believe the money will come somehow eventually.
Also soon I will bring back the Pro version and some of the new features will be available only for Patreon supporters. That should generate some income to help me keep this project (and me) alive :).

Best regards,
Juraj Mäsiar