"From" dropdown empty for non-admin users when trying to send email (8.9.1)

I have created another thread which explains in more detail my lost menues:

But to make long story short, I can log in to the CRM (both as admin or as regular user), login screen appears to be intact and works correctly. It is just that when I log in all of my navigation is gone (literally all) and if I manually go to (for example) suitecrm/#/Contacts and I choose a contact from the list, it will open my contact card and will show recorded data but all of the lables will be missing.

have you tried flushing your browser cache

yes, that is one of the things I do regulary

it happens on all of my computers, on two different browsers (ff and edge) and it will also repeat itself if I start completely freshly installed browser (windows sandbox, if you are not using it, try - this is useful)