Hey, I had the same issue with my PS5 can't obtain ip address error. Turns out it was my router's DHCP settings. I logged into my router (usually 192.168.1.1 or 192.168.0.1) and made sure DHCP was enabled. Fixed it right up! Maybe give that a shot?
Also, if you're not sure how to access your router settings, just google your router model + "login guide."
Also, if you're not sure how to access your router settings, just google your router model + "login guide."