Beyond just the visual, it appears the item stuck in the priority splitter is also counted with "Hold (all belts)", breaking circuit logic depending on an empty condition in a belt loop. This feels unintuitive when the belts have no visible items on them but the circuit condition still counts the ...

For some reason, deleting the input belt causes the the item to exit the splitter and enter the loop.

What did you do?
I created a loop of belts with "Hold (all belts)" and attached a splitter with an output priority that did not include the loop. I then filled the input belt with items that filled the splitter output and the splitter started to place items into the loop. I then stopped placing ...