Sorry, I'm a bit late to this conversation, however I have read the thread and want to go back to a question that
@AntiCheatAgent94 put to you regarding isolating net issues as a cause.
My reasoning is when I built my PC back in June 2020 I built it using my current MSi B450 Tomahawk Max, Ryzen 5 3600, and MSi RX 5700X Gaming GPU, and I was getting the same issues as you are experiencing, all other online games were fine, it only happened with CoD, so I sent back my GPU thinking it was an AMD driver issue and replaced it with an MSi RTX 2070, but this didn't resolve my issue.
I investigated my network, CoD/WZ seems to be particularly sensitive to network issues, and as my network ran through a Powerline connection with a Mesh Wi-Fi node being used to connect my PC over Wi-Fi to my router, I was getting quite a lot of internal latency added to my connection. After moving my Powerline to run directly to my PC and then swapping my Mesh node to where my Powerline was, I started getting more stable frame rates and better CPU & GPU utilisation. This improved immensely when my local area got wired for 100mbps broadband and I upgraded from my 35mbps.
The only way I can think of testing this theory is to try playing WZ 2 in the training mode, I don't know if this is an offline mode, but if it is, it should play fine with no issues and that will point to local network issues as your cause, if it is not, then I am a bit stumped for now.