PS4 Pro wi-fi not connecting

I have a PS4 and a PS4 Pro. The Pro does not connect to wi-fi. I get code errors saying "can't connect". I have tried changing DNS codes, etc. all no good. It connects fine w/ an ethernet cable. I have reset router, etc. Other point is that the PS4 connects to wi-fi just fine. So the network settings must all be ok.

I think there is a physical problem with the wi-fi module. I understand this is not a replaceable item. Is that correct?

Can I connect some kind of external Wi-Fi adapter to either the ethernet or USB port?

Any help would be appreciated. Thank you!