wireless backhaul fails often.

[sfx2000]

Note that it’s wl2, backhaul band. One thing that kept the nodes stable longer is setting gtk rekey longer. (Disabling with 0 doesn’t work, it just starts to retry immediately.)

You could try running following commands on main router and nodes.

nvram set wl0_wpa_gtk_rekey=2592000 nvram set wl1_wpa_gtk_rekey=2592000 nvram set wl2_wpa_gtk_rekey=2592000
I tried every combination of settings I can think of, but sooner or later my nodes enter this wpa loop (and there is also a dfs loop that just switch dfs status every second).

Respectfully disagree here... it's a security concern as what you are suggesting is to keep the group keys the sane for a month...

Find another way...