I think this is something to do with the engine where if you start creating instances within a tick, you can't pick them until next tick. For example if you change the condition in event 6 to plat_skin.UID=64 change anim, it will not change the anim, but if you pull this condition out of the loop and try it, then the instance can be picked and changes anim frame to 2, so this looks like a case of you cannot pick those created instances within the loop and must try a different approach. A possible approach could be to store the last UID of all the relevant plat_anim objects and then change them all together later on?