I use a Raspberry Pi as a WiFi Bridge to allow me to login to XFinity WiFi which is closer to my garage than my WiFi router (which is also XFinity – benefits of being a customer). Then all of a sudden I noticed that I had difficulty accessing a network. It appeared that I could not access a 2.4GHz band, just the 5GHz band and that stumped me.
What I found solved my problem is modifying the /etc/wpa_supplicant/wpa_supplicant.conf file to include all the frequencies on both channels and POOF problem solved.
freq_list=2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472 5170 5180 5190 5200 5210 5220 5230 5240 5260 5280 5300 5320 5500 5520 5540 5560 5580 5600 5620 5640 5660 5680 5700“
I also added a neighbors WiFi who kindly allowed me access to facilitate my Zwift training sessions especially in the winter. Fun challenge.