I have all 7 destination bins built, as you can see in the 1st screenshot in the post you replied to.
The ROM bin issue only seems to occur, when both bins reach full.
So the destination bin for my Coal is bin B, but I allowed that to reach max capacity, then I turned on Graphene, at the Purifier, to burn off some coal. The ROM bin continued to fill up, but did not empty into bin B, as the Purifier used up the Coal in there.
So my ROM bin had to be disconnected from bin B, then reconnected. When I did this it immediately began filling up bin B, again.
This has happened 4 or 5 times in 310 days.