Cannot connect to 2.4GHz

Installing and Using OpenWrt Network and Wireless Configuration
1

I have three r6220 and all but this one works on 2.4ghz. I can connect to 5ghz fine. I put my MacBook right next to the router and still cannot. I tripled checked the wifi password. This is what I get in the logs

Sun Jul 29 17:31:27 2018 daemon.notice hostapd: wlan0-1: STA c8:69:cd:8d:ab:56 IEEE 802.11: did not acknowledge authentication response
Sun Jul 29 17:31:31 2018 daemon.info hostapd: wlan0-1: STA c8:69:cd:8d:ab:56 IEEE 802.11: disassociated due to inactivity
Sun Jul 29 17:31:31 2018 daemon.notice hostapd: wlan0-1: STA c8:69:cd:8d:ab:56 IEEE 802.11: did not acknowledge authentication response
Sun Jul 29 17:31:33 2018 daemon.notice hostapd: wlan0: STA 9e:3d:cf:ec:ca:58 IEEE 802.11: did not acknowledge authentication response
Sun Jul 29 17:31:35 2018 daemon.info hostapd: wlan0-1: STA c8:69:cd:8d:ab:56 IEEE 802.11: disassociated due to inactivity
Sun Jul 29 17:31:36 2018 daemon.info hostapd: wlan0-1: STA c8:69:cd:8d:ab:56 IEEE 802.11: deauthenticated due to inactivity (timer DEAUTH/REMOVE)

Any suggestions on what is going on?

2

in dmesg i also have
mt7603e saying invalid mac address, using random address

Should I override all my MAC addresses for LAN & WAN and try again?

3

I have the same issue with one of my R6220s which shows the MAC address issue in the system log. I added my issue to another thread which is quite inactive as it is an old thread:
https://forum.openwrt.org/t/mt7603en-mt7612en-wifi-troubles-on-netgear-r6220/3705/35

And this is very strange in my setup: Right after flashing and configuring the 2.4G mode I can connect for maybe one hour with different devices. Afterwards connection attempts start failing with some, later all devices. 5G is always reliable. I assume it is related to the different versions of the R6220. In the other thread there were 3 different NVRAM layouts mentioned.

One user created three different firmware versions (but without any detailed description what has been changed). I didn't try them, maybe I am bit too skeptical.