First, Warzone is plagued with issues like FPS drops, low FPS, frame capping, etc. So the game itself might cause this. Secondly, you might want to undervolt the GPU by going into settings, tuning, "automatic", select "undervolt GPU" (this gives you the lowest voltage by the card's BIOS). Switch back to "manual" and input that into the voltage area. Disable zero RPM if that's on. Lastly if you're still having issues install the 20.8.3 driver using DDU in safe mode first. This resolves most issues in the 5000 series cards. These newer drivers lean more towards the 6000 series cards. The 5000 series are EOL products.
1.10mv seems a little high, not out of range but more voltage tends to destabilize these cards as opposed to the old days of more juice, more clocks. Check that your VRAM isn't running too high as well, the 5000 series isn't too happy with higher VRAM clocks. 1850 on the GPU is/should be fine. 1900 should work to be honest. Use 2 power cables for the card vs. the single/dongle deal. It can help since the card can pull more than 9A (14A) under load and that's all one cable can handle.
"It worked before you broke it!"