oh wow that sounds like exactly what's happening. Thanks for the quick reply!

I guess personally I still think this is a surprising behavior to ppl that couldn't find that particular thread (like me...). When I read "items inserted or taken by external entities" I was picturing inserters messing ...

Apologize first if this is not a bug but intended behavior, but I found it very un-intuitive at least and couldn't find an explanation on the wiki.

what happened

screenshot-tick-53258.png

So basically I'm trying to count items on the main bus by tracking all the input/output branches. Here ...