Transport shortcuts stop working after using AU plugins

I noticed that sometimes after using a AU plugin in the Fairlight page the transport control via keyboard (space and jkl) stops responding.

After some testing I think I have nailed it:
if you open the UI of an AU plugin (I tested with RX 6 Voice de-noise and DMGaudio Equality) and change something there while playing and then close the UI (while still playing) → space and jkl do not respond anymore.
Open the UI again, stop playback, close UI → everything is back to normal.
If you change parameters and close the UI while stoped → everything works fine.
If you open the UI without touching anything, close while in playback → no problem either.
The Fairlight plugins do not have this issue

Johannes

OS X 10.12.6, Resolve 15b7