Greeting,
I have found some interesting LVL number bug while i was lvling my pokes...at the start of battle, my Marill was 58, after he killed npc, he was 61 and lvling to 64 on one side, but on Poke view it was normally lvling, and after end of battle, the lvls get back to normal lvls they should (same as Poke view lvl)
I give you 3 photos of how it looks like.
Hope fast resolve.
Best Regards, Pele (Teemomain4ever)