Weak wifi signals on 1st floor and a way to run a RJ 45 port to bedroom 1 and 3

[SDISB]

 

[SDISB]

Thick concrete wall so I cannot drill through it, AP is a Asus RT-AX56Uv2 in mesh node mode, Router is a Asus RT-AX55. What should I do to fix weak signals for the 1st floor? and if possible how can I add a RJ45 port to Bedroom 1 and 3 without punching through walls for possible more mesh node placement?

 

[SDISB]

The signal is only weak when using 5GHz channels and is pretty stable at 2.4GHz and sometimes older devices (Wifi 4 n) failed to disconnect from the old APs when moving between floor. My Windows 10 and Windows 11 Laptop and PC seem to suffer from this as well although they are using Intel AX 200.