high ping; bufferbloat?

I've been experiencing high ping + latency issues main with gaming.

The high ping spikes and long durations of high ping seem to happen when my family is watching netflix/youtube.

**Something to note: I have a VPN service (NordVPN) and if I turn on the VPN and turn it off the high will be excellent (15-20ms) for a short period, then return to high ping.

* Restarted desktop PC, Modem, Router.

* I am only using a direct CAT-6 cable connected to the modem, tried replacing this cable too.

* Confirmed Windows is up-to-date, no pending updates, all drivers current.

* Xfinity has replaced my Modem in the recent past.

The top picture shows the average ping at the moment and the bottom shows the ping spikes that happen while others are using the network.