@771c7916 I recently had similar issues. Eero extender stations in my office, living room, and cinema room are on a wired LAN via in-wall cat5e’s (each of those Eeros has an extra LAN port, used by my 2 AppleTVs and iMac). LAN goes to a dumb 8-port switch upstairs, which is also connected to main Eero, whose WAN port is connected to ISP router. To try to resolve issues: rebooted all components one by one. Didn't fix until I got to LAST (unexpected!) component: the dumb switch!

https://media.hachyderm.io/media_attachments/files/111/166/677/810/902/492/original/8d3e761b87e18591.jpeg