Eero 6 router and Bluesound speaker disappearance

I use 3 Bluesound devices on my network: NAD T778 (home theater), a Pulse Mini and a Pulse Flex. The Flex roams around the house, depending on need. My mesh WIFI network is eero 5 (3 eero pros, one eero basic router). With this network, I use the basic router to travel with the Flex; once the WIFI connection is solid, I attach the Bluesound Flex via ethernet cable, and Roon sees this as an endpoint and streams well.

Until I added an eero 6 basic router as the roaming router. With this connected to WIFI, and the Flex attached, all seems well (blue ‘ready’ light on the speaker; solid white ‘active’ light on the router), but the speaker is no longer ‘seen’ in Roon. (Moving the router closer to another router, re-booting everything – still no Flex visible in Roon.) I verified, using the Bluesound app, that the Flex was still on the network: yes, the BluOS app ‘sees’ the speaker, but Roon apparently cannot. The eero app shows the speaker hard-wired to the router. So those connections appear active and sound.

I put the eero 5 back in and the Flex (re)appears in Roon, as it did previously.

I’ve combed the WIFI 6 and eero discussions, but this seems to be a different problem. It could be something about eero not ‘meshing’ with Roon (sorry for the pun), but in any case I thought I would post this in case others had a similar problem, were considering a similar move, or (better) had a fix. (eero support has yet to weigh in; I suppose it could be a problem with that particular router, but that seems unlikely, as it works otherwise, and the BluOS and eero apps see the speaker via that router.)