Hello,
I am not sure what the appropriate channels to report bugs are - if it isn't here, please advise where I should send something similar in the future, but I will not be doing it for this one (after all, I am spending my time improving your product, don't make we work extra please).
Issue:
G7500 running firmware 3.11.0-364021 connected with QSC Q-SYS Core 110f DSP (firmware 9.4.1) via USB (USB audio is disabled, using analogs for audio).
Mute sync works great both ways, except when g7500 is a sleep, with "Enable Mic Mute in Sleep Mode" enabled (default setting). In this case, while g7500 is a sleep and Q-SYS HID block sends a Mute command, it appears to receive Mute off feedback, but when the g7500 wakes up it comes on muted, which does not re-sync with Q-SYS.
Disabling "Enable Mic Mute in Sleep Mode" in g7500 settings is a workaround - I can mute/unmute during sleep and it is always in sync with DSP.
P.S. After I drafted the above, I decided to test with a second 3rd party DSP - Biamp Tesira Forte + EX-UBT (their expander providing USB HID) - same exact results. Since we have confirmed issue with 2 different DSP, it am certain this is something Poly will have to look into.