Studio blackout if dock playback bars switched too quickly

Hello,

Running v3.19.1 with two net 1 networked Full Boar 4 consoles.

Playback Bar 0 with most Masters at 100%

Playback Bar 1 with one Master at 0% and the rest empty. 

If I dock them too quickly, all masters either jump to full, or ZERO as I just found out in the studio when I switched back too fast and I blacked the studio out. Not ideal. 

Cheers 

Colin