[1.1.106] Inserter not dropping items on both sides of splitter with output priority set and different splitter behind

[SIGSEGV]

1. Place a fast splitter and a stack inserter inserting into one side of the splitter. Items from the inserter end up on both splitter output belts, as expected.
2. Set priority output on the splitter. (I prioritized the "far" side from the inserter in the screenshot, but it doesn't seem to matter.) Items still end up on both output belts, as expected (since the inserter can introduce items faster than the priority side can drain them, as long as stack size > 1).
3. Add a basic or express splitter behind the fast splitter, with its two outputs feeding into the two inputs of the fast splitter. Unexpectedly, the items from the inserter now exit the fast splitter only on the priority output side; the inserter blocks until they drain.

This issue occurs whenever the two splitters are of different types/speeds. The screenshot and attached save show all combinations of "inserter splitter" (each row) and "other splitter" (each column, including "none"). The only combinations that behave as expected are when there is no "other splitter" (leftmost column) and when the two splitters are of the same type (diagonal from bottom right to top).

screenshot-ins-prio-splitter.png (1018.85 KiB) Viewed 225 times

After some more experimentation, I found that it's sufficient to place just a single belt of a different type feeding into the inserter side of the splitter, regardless of which side has priority.