I have iPhone XI, and Wifi worked flawlessly until updated to 14.1. Then did 14.2 in hopes it would fix the glitch. But it did not. If anything, it is worse. I have done everything suggested (Private network is off; I have reset Network settings, and so forth). I now basically must keep my phone OFF Wifi for ANYthing to function. News apps, logging into my bank, searching on Safari and so forth. Luckily I have unlimited data, but it slows down after a certain usage, so I am FURIOUS that a simple update did this to my phone. My phone also now shows read receipts when it feels like it, though I have that toggled to off. I tell my boyfriend to tell me if "delivered" switches to "read" and then I toggle it on and then off, and that seems to temporarily fix that. Phone also gets hot now. And battery drains far more rapidly than before. Most upsetting is I literally cannot use my WiFi at all. APPLE MUST FIX THIS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I just did manual reconfiguration of DNS server per one of the suggestions below, and IT WORKED. My Wifi is now working. Wow!!!! Thank you for the help, but it is still reprehensible that Apple did this to all of us and isn't helping, and that some random person helped me from this blog. Follow the directions to reset DNS server to manual instead of automatic in Network settings, and type 8.8.8.8 and in server 8.8.4.4. My WiFi now works perfectly!!!!