This is caused by the mobs falling on the edge of a slimeblock
Open minecraft and select options,
Go to controller settings and click tap right trigger on list not controller,
then click the trigger on controller and it should work perfectly then!
Is the back of the house in another biome and get overlapped?
@Neko
this website is a web service belong to Mojang and its important that the website t report bugs Dosnt have a bug itself