Wifi dropping randomly, latest Big Sur, Late 2013 MBP Retina

Wifi dropping randomly, latest Big Sur, Late 2013 MBP Retina.

This problem has been ongoing for months, im on a semi open network (unsecured open with a splash page pass code). Wifi on Big Sur drops randomly, sometimes 20-30 minutes, sometimes 2-3 hours, sometimes 8 hours. have to manually select the network again to connect. I have all the latest software, OS (cant upgrade to monterrey)

I did notice recently it appears on both 2.4 and 5 Ghz networks, when alt clicking the wifi icon, so the router must have switching enabled for optimization. this may be a factor in the wifi disconnects, how it hops between the two networks trying to optimize?

rssi isnt so good at times -70s so maybe optimizing coverage could help lower that number

2.4Ghz 20Mhz

5Ghz 40Mhz

Ive tried doing custom scripts to ping the router to maintain connection with it to no avail, it just drops and I have to reconnect the network every so often.

I will test some other devices, ipads, windows laptops, to see if the network drops. but i suspect its just certain mac models with this annoying issue that apple cannot fix after a year +? i dont get it..