I just summoned a bunch of iron golems to see what the various evolutions were. and now i have 1 with 13 exp (lvl 1) and another 4 with 0 exp (lvl1) that i cant level up. i have tried to resummon, i have tried with only low level creatures, mixed level group, lvl 1 realm, lvl 10 realm. Now im concered that i can never level up new creatures unless i start a new game.
UPDATE: backed up local data, updated, and verified files, and now experience is going up on the golems.