@Hannibal_Lack had done that, wifi is fine. Three PC's on ethernet suffer the same fate. The only remedy I have found that seem to work is to reboot the modem before I use the PC.

Same issue as here: https://forums.whirlpool.net.au/archive/2705648 - VR600 - PC with Realtek LAN - Window 10 My Internet through LAN drops out daily, however my LAN shows as connected with no issues...