Weird internet downs

[wireless]

We have Telus fibre 150, unlimited internet bandwidth (as far as I know), the 3200 modem and a TP Link 16 port switch downstream.
We use Optic for TV and have mostly one TV running out of 3 connected at a time. I also have a kid hoocked up with a PC that he uses for gaming. Another kid has an XBox1

No matter if two of the kids are playing online or one. When’s either quits playing my whole network goes down. TVs freeze, the other kid’s game freezes too.

If I go to the switch and disconnect the Xbox or PC, or both if both are online... all goes to normal.

I sometimes notice the modem light on the port to go dead. When I change the ports that the switch is connected to to difrent port.. I get a blinking green light again.

Any thoughts?

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