Factorio Forums

there should be 8 items on the upper belt instead of 7.

the upper belt is reading items on it and the lower belt only let them pass as the upper belt is full ( 8 items )
this way the Kovarex process always has enough dark uranium before letting the extra go to munition production.
But at this moment production is halted because the upper belt won't fill up completely for reasons unknown to me.

edit: changing the direction of the upper underground belt does something to the compression of the belt being read and it has 8 items again, after that it is working correctly again.

Side loading does not guarantee 8 items on a belt since no insertion point is at the start ot that belt. Not a bug.