I have this same issue. Fresh BF 2042 install yesterday. All drivers up-to-date, even clean installed.
It isn't as bad as adding super significant time onto the respawn menu but is quite bad.
To be clear this isn't throughout the whole game. It is fine when it boots up but as soon as a game mode, e.g. All Out Warfare is selected, about 5-10seconds into the menu/character screen FPS has dropped below 10 from often over 150. Going back to the game mode menu or any other menu does not fix this. Tabbing out and then back in will occasionally fix it for a second or two. It is not just a slow FPS either. It is a slow responsiveness with the Render Latency in menu hitting over 400ms.
The active game experience itself has similar performance to everyone else (no real complaints there), except for when in the respawn menu where it drops again to teens or single digits.
What does seem to work for alleviating this generally is running the game in Windowed mode, Full screen and borderless have extensive lag as described. If maximized in Windowed mode the issue comes back but when just slightly under maximized in windowed mode everything is fine. Occasionally in not-maximised windowed mode switching menus will cause the FPS drop again; adjusting the window size fixes this. Something about full screen/maximized/the window is causing this menu issue.
Windows 11
CPU: 10700K
GPU: 3080 FE
I had horrible menu lag but when i changed Fullscreen mode to "BORDERLESS" it stopped alltogheter.
