Hello ,
It seems this fix your issue
I dont know why but the last 4 hours i was searching for the problem using the disable method (remove events until the issue gone) i thing this was the problem.
Maybe another guy can tell us why other sprites pathfinder behavior mess other sprites pathfinder behavior.
Also you cannot set as custom obstacles same sprites, you have to add them as family and then add the family as custom obstacle.
Using families you can reduce your code in lot of events.
And it seems that effects cause extremely high CPU usage so its better to avoid it.
Ah , you can use subevents
use this