[0.17.4] Splitter priority not working properly

[chagnons21]

I noticed that a splitter in a sushi belt had a weird behaviour. Turns out it was all of them.
Every so often, an item from the lowest priority input was passing through even if both inputs of the splitter were filled.
Here is a video of the issue in action:

factorio_0.17.4_bug-report.mp4

(6.87 MiB) Downloaded 149 times

As you can see, even if the left belt it filled and prioritized, items from the right belt sometimes manage to pass through.

I also included my save file and my log file though I don't think they will be necessary because I tested it on multiple files, generated on both 0.16 and 0.17.

Thank you for your tremendous work.

[Rseding91]

Thanks for the report however this isn't a bug. "priority" doesn't mean "only". It just prefers one over the other but the other is still free to move.

[chagnons21]

Has that been changed? Since the prioritized side is fully stacked, shouldn't it, by priority, output only from this side?
The same setup used to work as I described in 0.16. I find it weird that the prioritized side has to stop for the other one. I feel like that rather defies the purpose of the priority.
It "invalidates" a lot of my sushi belt designs. I'm not complaining, I'll find another way, but I just wanted to make sure this was not a bug.