The eARC compatibility issue between Optoma’s UHZ66 and Sonos ARC is the result of unconventional CEC timing by the Sonos ARC. Optoma has attempted to “compensate” (workaround) for the timing with limited success yet continues to be work in progress. We strongly recommend reporting this issue to Sonos (as well). We will provide an update to this situation in the coming weeks.
USA Support