Hi,
Obviously I can’t comment with regards to your experience with them, but hopefully I’ll have more luck than you here. I can prove where CEC is being problematic in the chain, and it’s overwhelmingly on the Optoma’s end in negotiation and RX.
Can you upload debug logs from one of those systems, ideally LE as it’s Linux based, and then OSMC so I can compare things?
Can you also ensure that on both tests they’re connected to the same HDMI ports (both in to AVR and AVR out) as well as with the same peripherals attached to AVR/TV?
Cheers
Sam