So far I've discovered the following issues (Evernote version 10.0.10 - OSX Catalina 10.15.4)
Can't create new tags when selected multiple notes.
Can only select up to 50 notes.
Cannot select multiple notes and drag to new Notebook, only first one moves.
After selecting multiple notes (50) from Notebook A and using the blue UI to move them to Notebook B it took over 5 minutes of spinning green circle.
Needed to do this multiple times spending 20 minutes to move 200 notes. - This is a task that would have taken seconds in my previous version of Evernote
Some notes that are visible in Notebook A when dragged to Notebook B notification informing me selected notes are already in Notebook B and I am unable to move them
All actions related to notes moving making Macbook take off, fan running very loud for extended periods of time.
Regretting updating