I have almost the same problem
the Aimesh node frequently shows poor signal despite the signal is always -48
the uplink shows 2.4 GHz
the internet is very slow at the node level
moreover
the nodes always drops the connection
several trials of rebooting,resetting ,factory resetting both the node and the router is useless
both are updated to the latest firmware
XT8 zen Wi-Fi is supposed to be the flagship aimesh of the ASUS company
many suggestions??