While trying different inbuild Battery effects it suddenly happened that when I turned on Battery own inbuild Reverb that the audio track muted. I switched the Reverb on/off several times and the audio track was unmuted upon turning off the Reverb and muted again upon turning the Reverb on. Two more klick and everything went back to normal. This did not happen before nor did it reapear when trying the same thing.
No idea what's wrong with that, but it's a bit worrying to see an inbuild effect of a VST that is running on a different track to be affecting clip playback.