I was having a recurring issue where the Pi 4 was dropping off the WiFi Network overnight and required a reboot to resolve.
After some research I discovered a fix which has been working for me.
I set the country code in the /etc/wpa_supplicant/wpa_supplicant.conf to be the same as the country code on my router.
This was the first line in the file:-
It would be great if this could become a standard parameter.