OK, so we've got about 2 or 3 simultaneous conversations pointing towards the same issue. If there are intermediate switches between the master router and the AImesh nodes, your best option is to disable the dedicated Ethernet Backhaul mode in the "new settings panel", and instead have "Ethernet preferred" in the "old settings panel" enabled. Some people can make it work with dedicated Ethernet Backhaul and some can't, reasons why unknown, but seems to be switch dependent.
Thanks, that's good to know, as I suspect i've been beating my head against the wall due to this issue since I started beta testing. My question is, why isn't that just automatic? It seems to me that if an AiMesh note has an ethernet connection to the main router, shouldn't it try that first, and if that fails try via Wi-Fi?, without the user having to know to enable those settings? Oh well, at least I have an answer as to why I couldn't get it to work, so progress is progress.