I have an ongoing problem with this S21+ that I've had a few weeks. Every once in a while I'll notice it is no longer connected to my home wifi. If I go into Wifi settings and get it to connect, it will come back with "unable to authenticate". Nothing has change, password is the same, it was connected earlier. No other device in the house has a problem. I've read a lot of vaguely related posts, and I can get it to connect by going into airplane mode then turning on wifi, but it is short lived (like an hour or two). I've turned off the Mac address randomizing, still doesn't help. I've done a reset on network settings, again only fixed it for a few hours. The only thing that fixes is it is a reboot of the phone, and that lasts a few days, and then the problem comes back.
I saw that, thanks, but I'm not really willing to do that. There is no reason I should have to provide my phone a static IP address on my router, never had to for any previous phone.