Just to confirm: 15.23 Fixed it. They're happy and consistent now.

Thanks for the reply, lookin forward to .23!

... Either the ones on the bottom are bugged or the ones on top are. They are behaving differently, even though they're all made with the same blueprint. Either way is fine, I figured there must have been a change like you mentioned, but shouldn't they work consistently either way?

Some of my logic-controlled inserters will drop an item on the belt, others won't until the process runs through again. They are all the same blueprint but behave differently.

Screenshot below shows inserters on the top row (except the one on the far right which started off not working as expected ...