Sonos Drop in odd place

@support i have a strange new issue with my Sonos setup. Suddenly, after working well, one of the Play 5’s (gen 2) is unavailable in Roon. It works perfectly when grouped with my other four Sonos when I use the Sonos app. Never a problem. it appears in the Roon app but when I include it in the zone nothing plays anywhere. When I disable it everything is fine on all other players. So strange. I have a Boost setup and very strong connection so its not that. Never a problem with the Sonos app. I cannot figure it out. How can it work perfectly in Sonos and totally bring Roon to a halt? (and this is with hi bit rate, low bit rate, internet radio, does not matter. No exception.)