Most of my issue has been stated in this previous bug report https://www.pixelmonmod.com/tracker.php?p=2&t=14148. Sometimes after finishing a wild pokemon battle my pokemon would instead of evolving into their next form, evolve into themselves thus nullifying evolution in the same way hitting cancel does. This does not happen with trainer battles though as evolution goes through like normal. The second part of the previous bug report seems to have been fixed though, levelling said pokemon who didn't evolve after the battle evolved just fine after the wild battle via rare candy/trainer battles.

Linking to new master ticket: tracker.php?p=2&t=14241

(closing this one)