Internet dropping when on discord or party chat

Xfinity support says I have full internet, but connection to my PC and Xbox drops every few seconds. I have a wired connection for both and all speed tests say I’m getting internet. If I try and play online games they won’t open or will kick me out, and if I use discord or Xbox chat, I am disconnected and reconnected every few seconds. Also, when on my pc, turning on my VPN sometimes fixes the issue which I thought might somehow help explain what’s happening. Xfinity says it’s a problem with discord but I know it isn’t because it’s happening on my Xbox as well as my PC. Anyone have a fix for this?