When ever we get posts about graphics issues on a system that only glitches when playing Call of Duty, my usual response is to talk about connection issues, it's not alway server based, as can be seen here and in my own case, where some re-arranging of my router helped resolve nearly all of my issues. But we can see it was a connection issue, because moving the PC from 1 location to another internet connection fixed the issue.
80c for a Radeon 5700XT is nothing to worry about, but if it is a concern, add more intake fans to blow into the GPU if possible, that card has a T-Junction of 100c, so you're well within safe running temps.
Ping shows the speed at which you can send out a request and get a response from a network location, nothing else, it doesn't measure the quality of your connection, just the speed of response.
Connection quality is measured using jitter, if you look at this plot of a graph that shows download and upload speed using speedtest.org you will see that it is smooth graph, indicating that there was a steady, clean, download or upload test, a connection with high jitter would not be smooth and flat, it would be filled with peaks and valleys.
View attachment 1247
This test is not giving me a full picture of what's happening with my connection, there are no figures for packet loss or jitter, I am sure Speedtest used to do it, the Android app still gives Jitter results, but that jitter might be a result of the wireless connection between my device and router.
See if you can google how to test for jitter, it's not very easy, iirc, but it will help you pin-point if the fault is in your home, which your ISP is not responsible for or if it happens before the internet connection reaches your home, which your ISP might be responsible for.