Mouse sensitivity drops severely after closing map screen

I’ve got a map screen that’s powered by switching temporarily to a pawn with SceneCapture camera looking at the level. Sometimes, just sometimes, when I close the map widget my mouse sensitivity drops to almost nothing.

I’m testing this by wiggling my mouse dramatically, going into the map for a while and panning around, then closing it and wiggling my mouse again.

So that this isn’t just a question of vibes, I’m recording my frame time and yaw rate before and after I open the map, and then cleaning up and summarizing both datasets in Excel. That recording code (in my controller) looks like this:

The results are VERY interesting. You can see that my average frame time is about the same before and after, but my turn rate is dramatically lower.
image

And if I slam those datasets together, here’s a graph of all the per-frame yaw rates I recorded. See that drop? That’s where the menu opened.

I feel like I’m going crazy. I’m not looking at the turn rate of my pawn, I’m looking at the base axis value. Why would that ever change in such a consistent way?