Very Slow Wifi - generic question

[Frood42]

For some reason, my Wifi speed dropped down to 20-30 Mbit/s.
On WPA2, 2,4 or 5 GHz it is very slow. On all channels. On WPA3 it is better, 150 Mbit.
But on LAN cable connected to the router, I have 500 Mbit stable.

Some day, something happened, maybe some interference occurred or something that is in conflict with my Wifi.
I have tested the vanilla original OpenWrt Image on R7800 and C7 to be sure it is not depending on my custom image.

There are about 10 other Wifi Around, 2-3 each on channels 1,6,11, so not very much.

Is there any chance, any kind of analysis that can be done using OpenWrt to see why the speed is that low?
MacOS has the built in functionality that scans for Wifi and it suggests the best channel for 2,4 and 5 GHz, but this doesn't change anything.

This is totally weird.

I have also moved the router 5 meters away from the current position, no difference.

Cheers, Frood

[Frood42]

BTW, is the how it is supposed to be?
I see Generic 802.11bg for both, radio0 and radio1

/etc/config/wireless

config wifi-iface 'wifinet1'
        option device 'radio1'
        option mode 'ap'
        option ssid 'ABC123456'
        option encryption 'psk2'
        option key 'Password111111111'
        option disabled '1'

config wifi-iface 'wifinet2'
        option device 'radio0'
        option mode 'ap'
        option ssid 'ABC1234561'
        option network 'lan'
        option key 'Password111111111'
        option macfilter 'deny'
        list maclist 'F0:99:B6:1D:2A:B3'
        option ieee80211w '2'
        option encryption 'psk2'
        option disabled '1'

config wifi-iface 'wifinet3'
        option device 'radio1'
        option mode 'ap'
        option ssid 'ABC1234563'
        option encryption 'psk2'
        option key 'Password111111111'
        option wps_pushbutton '0'
        option network 'guest'
        option disabled '1'

config wifi-iface 'wifinet4'
        option device 'radio1'
        option mode 'ap'
        option network 'rob'
        option encryption 'psk2'
        option key 'Password111111111'
        option ssid 'ABC1234565'

config wifi-iface 'wifinet5'
        option ssid 'ABC12345677'
        option encryption 'psk2'
        option device 'radio0'
        option mode 'ap'
        option network 'rob'
        option key 'Password111111111'
        option disabled '1'

config wifi-iface 'wifinet6'
        option ssid 'ABC123456222'
        option encryption 'sae'
        option device 'radio1'
        option mode 'ap'
        option key 'Password111111111'
        option network 'lan'
        option disabled '1'

config wifi-iface 'wifinet7'
        option ssid 'ABC123456111'
        option encryption 'sae'
        option device 'radio0'
        option mode 'ap'
        option network 'lan'
        option key 'Password111111111'

[Frood42]

It seems like this made a big difference:
old config:

## # CONFIG_PACKAGE_ath10k-firmware-qca9984-ct is not set
## CONFIG_PACKAGE_kmod-ath10k=y
## # CONFIG_PACKAGE_kmod-ath10k-ct is not set

new config:

CONFIG_DEFAULT_ath10k-firmware-qca9984-ct=y
CONFIG_DEFAULT_kmod-ath10k-ct=y

now speed is up to maximum of 500Mbits/sec on 5GHz