Update screwed my setting of Firefox

My Firefox browser has just been updated .. not by me but somehow .. to 140.11.Oesr(64-bit) Its completely messed up all my settings .. why? Its taken me the best part of this morning to sort everything out . All my bookmarks were not displayed, the web pages that should have been displayed on startup weren't.. and to cap it all the "Done" button is hidden at the bottom of the page .. and why is it needed  ? all other setting just need to be changed to set them. Its so annoyed me that I've downloaded Chrome. and I'm using Opensuse Leap!