Bose S1 Pro + signal drop off

I have 4 S1 Pro + and all of them are doing the same thing. It seems there is a signal/volume drop that randomly happens.
A perfect example: Playing a guitar Chord the sustain drops off… cuts off mid sustain.
Vocals are randomly dropping in volume.
All the S1 Pro + have the firmware update.
I am plugged in direct, I am not using wireless, and have tried different mics and guitars and the same thing happens.
It happens with plug in power and also on battery.
Any help would be appreciated.

Old topic but still… I noticed the same thing when the “Expanders” feature of Bose is turned on, so you could try turning that off.
I almost can’t use my piano Roland FP10 without expanders cuz the Bose is giving a HUGE hissing sound from all channels all the time.

So to me, this is basically unusable :-/

Did you manage to solve it somehow?