Hi,Biscuitdad, the following link might help you…
https://www.lifewire.com/reset-network-settings-on-mac-5184072… it also depends if you have an Intel Mac Mini or an M1 Mac Mini, which you can find about by going to the big apple icon, top left of your screen > About this Mac….. that i don’t know .. if you have an Intel Mac Mini, then follow apple support’s instructions on resetting the smc/pmu and zapping the pram 4 times on startup.. that usually works, on M1 Mac Mini’s you can’t do that… as there is no pram to zap… this other link may help, though it doesn’t mention M1 mac minis : https://www.macworld.com/article/671570/how-to-fix-wi-fi-on-mac.html… otherwise the usual old trick might work: shut down your m1 mac mini…. Disconnect power cable/cord from mac mini… leave it unplugged for about 10 minutes or so ( go grind and make a pot of coffee if you drink it and like it, if not, go do something not Mac or computer related… then come back after that, reconnect/ plug in the power cable/power cord to the Mac mini and press the power button to turn it on and start it up… you may also wish to buy and use a wifi booster/extender of some kind.. i use an old Airport extreme which extends the wifi of my airport time capsule… here’s a dumb idea: ( so dumb it might actually work/be doable… be OK… do you actually need Wifi on all devices? Could you not use the Mac mini’s built in Ethernet Port ( or are those not standard and built in/ included on your Mac mini!? ) i though they were… i thought it was a given, eg “of course it has an Ethernet Port-well, duh ! “ but with this recent crop of Macs nothing is set in stone anymore… anyways.. it should look like this and should be on the back/ rear of your Mac mini : 

well, shoot, i tried
john b