I have tried resetting the router, and had it replaced. None of my other non Android devices do it. I have factory reset my phone as well as reset network settings. I have tried giving my phone a static IP. When it happens I can't even click the network to connect to, it stops responding.
I figured I wasn't alone. This is happening to my wife and my father in law, making it a problem in my house and their house, States away, with a different provider.
Same boat here. I believe it started happening as soon as I upgraded my S10+ to OneUI 3.0. It wasn't happening with OneUI 2.5. And I've tried 2 different routers, different WiFi networks. Same error. When I click on it to connect, it connects successfully, but after a while, it disconnects with that error.