It works, but a) WiFi speed is very slow (like 10 Mbps as opposed to 100-200 I had on Eeros in the same locations) and occasionally I either I get droped or one of the devices just drops.
I selected channel 6 and channel 40 for the 2,4 and 5 Ghz bands respectively on all three devices (they're each broadcasting 4 SSIDs) after a scan to minimize interference (I'm also running Zigbee to didn't want to use channel 1 on 2,4 Mhz).
Thanks for the split, as a side quest I'm trying to set up a mesh as an alternative (I saved the other configs though). Interestingly the signal got slightly better (like 30 instead of 10 mbps) when removing 1 out of the 3 devices (not the AP of course, but one of the others regardless of which).
I did some more experiments and tried mesh, too (not roaming, although that's enabled as well).
While mesh is more reliable in terms of connection, it is still slow (around 10 mbps on the third device (farthest from the one connected to the main router via cable). Right next to the first one I get around 70 mbps. Odly enough I have a higher upload than download speed?
I'm on 2.4 Ghz only atm as the 5 Ghz seems to have major issues in terms of reliability. I'm not sure what the root cause is, but I have a very bad signal even directly next to the devices (regardless which one and I also tried different channels and did a channel analysis -> I'm basically on my own on the 5 Ghz band so I can pick whichever channel I want. I tried 36, 40 and 44 so far).
