DO NOT USE THE REMOVE EVO FEATURE
I just talked to a supervisor on EA help, and removing the evos off of a card gets rid of the evo entirely from your evo page, do not use the feature until a patch has came out for the issue.
Ideas
This isn’t a bug. If you apply an evolution and then undo it, then that evolution is gone. However, if you applied a repeatable evolution, hit undo, and now all repeats of that evolution are gone — that is an issue.
The second issue is the correct one, sorry if that wasn’t clear.