Has anyone had trouble connecting Samsunf QN85 to a Sonos Amp?

I just upgraded from a Samsung Qled 70" to a Samsung 75" QN85. I tried connecting the same HDMI to my Sonos Amp but I am getting a message on the Samsung 75" tv "Your audio device is connected to a port that does not support ARC. Please connect your device to the HDMI3 (Arc) port." I ensured it was installed in hdmi 3 port. I followed all the protocols to activate arc through the menu and turned on CEC. I've factory reset it and turned on arc different ways. The screen recognizes the sonos amp hdmi but it flip flops between tv speakers and the sonos. It plays sound on the tv speakers but no sound on the sonos. The tv diagnostic recommended to switch hdmi cables so I did so. No change. And it continued to flip flop. I tested all the wires with an hdmi tester and they all passed. I bought a sonos beam to connect to the hdmi 3 and connected with no issues. It just wont connect to the Sonos amp. EXCEPT I connected a sonos optical connector to the hdmi cord and plugged it into the optical jack on the Samsung. I changed the audio to optical and itsounded properly on the sonos amp and sonos speakers. BUT i was unable to control volume on the samsung remote. I could only control volume by touching the volume controls on the amp itself or the Sonos app. Need help in connecting TV to amp through earc?