Nightly builds freezing on windows focus loss

Hi,

I recently updated to using the nightly releases of SDL2 (via https://buildbot.libsdl.org/sdl-builds/sdl-visualstudio-amd64/) and since doing so, our game will freeze approximately 6 seconds after losing focus on windows.

Now I understand this is not the correct place to report bugs, but am curious if this is worth reporting on bugzilla, and if so, which version do I specify when reporting. Also would be interested if anyone else can reproduce this issue (using a GL context).

In some brief investigation it looked like it may be related to SDL_WINDOW_EXPOSED events being handled incorrectly, but I have nothing solid yet.