(Known issue on GitHub) Fermata playback broken in 4.x nightly build
1) Load a score with fermatas, and make sure they have a time stretch value set in their playback menu.
2) Play the score
You will see that the visual side of the playback respects the time stretch of the fermata, but the audio jumps forward.
Sorry if this is a known bug. Just trying out some MS 4 stuff and it caught my attention almost immediately.
I have a screen capture of this here: https://youtu.be/XPJFJEs1Z28