I use Acrobat on both Windows PC and Mac (latest Windows 11 and Macos14 sonoma). I downloaded Acrobat from Creative Cloud and kept it updated all the time. A few months ago i found the Acrobat UI was changed on my Mac and when i finally got used to the new UI, recently it just changed back to the old version again by itself and i no longer saw the UI switch button. It's really annoying. And one interesting thing is, the Acrobat UI on my Windows PC never changed even though i used the same account in Creative Cloud.
Another problem is that, when i added signatures or initials, i selected "from images" and finished signing this time, but the next time if i wanted to select other images, the old ones couldn't be replaced or removed until i re-installed Acrobat on Mac.