Hi there, 
Here's my area, about 80square meters
distance between routers is 11 meters.

one ssid, smartconnect on, transmit power LOW

with two AX23's routers and ethernet backhaul easymesh i had no problems with wifi:

wireless clients (only wifi5 ac) always have 5ghz AC connect in zone 2,3,4,5 
2.4ghz connect ONLY in zone 1,6 (wery very thick walls) - client always switch to 2.4ghz and immediately switching back to 5ghz in other zones.
everything is fine, perfect mesh, perfect roaming MAIN-SATELLITE and back.

(i use android samsung m34, a50, s20, xiami... and iphone14. wifianalyzer to see which router is now connected)

BUT
REPLACING satellite ax23 to archer C64 (just connected power+lan+updated to last firmware 1.13.15)added it to mesh:
once ANY client is connected to satellite, it always keep connect to C64 with 2.4ghs speed in zone 1,2,3,4,5. 
even when main router signal is much better:

On screen you can see, my mobile is near main ax23 its 5ghz signal is much stronger but still is connected to SATELLITE 2.4GHZ with-57db.

only when 2.4ghz signal drop below -70db in "zone 6". it will roam to main ax23 2.4ghz and immediately switch back to 5ghz in zone 4-5 

ax23 stiching 2.4-5-2.4-5ghz no problems

C64 doesn't want to let go his clients, always keeping slow 2.4ghz connect

maybe bug in 802.11v so it haveonly "ONE WAY" to 2.4?