The attached junction doesn’t work. There’s enough input to feed four pill packers, but nothing is being sent to the fourth even though the arrows are all in the correct direction and there’s an obvious place to send it.
I’m not sure what you are trying to gain by combining those 2 lines; 1 input port to 2 pillmakers and other input port to 2 other pillmakers will give you maximum output.
But, in any case, it looks like you have a “non-deterministic” T-belt at the input to the 2nd pillmaker near the top. It doesn’t know to be a “SPLIT” or a “MERGE” (you’re trying to make a SPLIT) so it won’t feed the Crossroad belt (at the input to 3rd pillmaker) - so it never feeds across to the 4th pillmaker. that’s my guess anyway.
SCHMID6SIG is right I think. Also the crossroad isn’t helping. In this setup I believe the 4-way belt you have is acting as a crossroad rather than a splitter, therefore it will only send drugs in the pill printer straight across it.
The solution is simple: don’t connect up all of the lines. Just split each of your two lines across 2 pill printers.