Why is the enhanced input system "consume input" setting broken?

Higher priority mappings always block lower priority mappings which means this tooltip is wrong and the input system is broken (or maybe I’m completely missing something)

Here you can see I have copied the input and hand poses from the Epic VR template into my 5.2 project, the thumb input won’t work unless I set the priority to a value above 2 so it’s higher than my other mappings which use thumb controls (like snapturn), which is fine and makes it work, except it then means the other lower priority mapping contexts now don’t work.

This makes no sense though and appears to be a bug because you can see here the thumb input action does not consume input, none of hand poses do, but it still blocks any lower priority mappings that use the thumbstick. What is the point of the priority/consume input setting if it has no effect and still blocks everything else lower?