Wifi losing internet connection (while still connected to router)
I would try again after a Safe Mode (restart holding Shift ⇧) and see if the results are the same. Also, could you try using Ethernet to gauge the difference? Is this a laptop? If so, is there a case which could be removed? Any new equipment nearby (ie an electric fan, metal filing cabinet, etc.) which could be disrupting the signal? If it is a laptop, it is entirely plausible that the internal antenna has come loose or damaged (any repair or upgrade work carried out?).