When I turn on my PC, a different PC on the same router loses internet connection for a few seconds.

Two PCs are both hard-wired to the same Nighthawk R8000P router and IP addresses are DHCP-assigned. PC1 is on all the time, PC2 gets turned on and off daily.

When PC2 is turned on and the wired adapter connects to the internet, PC1 loses its connection for 2-3 seconds. It comes back immediately, but that's long enough for the user to get booted from online game, discord, whatever they're in.

I've tried setting DHCP reserved addresses for one, and both, on the router but that didn't change anything.

If I unplug the ethernet cable from PC2 and let it use WiFi on startup, there's no problem. Only happens on wired connection.

PC1 is Windows 10 Home, PC2 is Windows 10 Pro.