A few weeks ago I noticed i had a strict nat type while playing games like Warzone. I decided I would port forward the IP associated with that device so that my Nat type would open. I was successful with this and I saw a small improvement. However, in the last week my internet as been absolutely horrendous. I constantly get the connection issue sign on Warzone and Fortnite (rarely ever have gotten it on fortnite).
My ping jumps between 60 and 150 so aggressively even though my Nat Type is on "2" and I get speeds of 50mbps upon testing it on my PS4. I dont think other devices are having this issue in my house.
I use a powerline adapter which I have been told effects latency and ping but this is horrendous right now, much worse than ever before and its almost impossible to play.
Unfortunately, just like the 10s of threads titled with this exact issue it doesn't look like VM can offer any solution.
Keep calling up and complaining over the phone. Have them file an official complaint and keep your fingers crossed that by the 50th time you've called they've fixed the over-utilisation issue in your area.