Video calls slow down my entire internet

Hi,

This is a unique situation I find myself in, but i'm not sure what to do or why this is happening. Whenever I go on any video calls (keep in mind my internet should be 100 down/5 up), my entire internet grinds to a halt, dropping my speeds below 1mbps. I've tried resetting the router and the modem. Does anyone have any experience with this issue, and how to fix it?