Hello!
I've had this issue for a while in BF6.
When I enter the game and get into the menu, it will start lagging SEVERELY. Like 5-10 FPS.
I have performance overlay in the game in the top right corner and both CPU and GPU are at the same numbers and they are usually around 5-10.
When I get through the lag hell and get to queue and come into a game, the FPS is just fine. So it's related to the menu.
When I've played a game, the menu runs just fine.
OS: Windows 11 25H2
CPU: Intel Core Ultra 5 225
GPU: RTX 5070 (edit: I accidently wrote 3080 which was my previous PC - upgraded not long ago)
Storage: Obviously nvme2...
Battlefield is the only game I am having trouble with so it has to be a menu bug even if I'm one of the few who might have this issue.

check your graphics option in game for fps limit in menu? You may have set a limit for it and forgot.

check your graphics option in game for fps limit in menu? You may have set a limit for it and forgot.
Limit for FPS? I have it set to one FPS over my refresh rate.
Anyway...
Cleared caches (shaders) in different places so it enforced Battlefield to what I thought was recreating them but it said it was just validating them for like 5 minutes...
Issue is still there but I noticed that if I alt+tab to another program and back into BF6 again, the FPS will be fine. So maybe it's tied to the "fullscreen" in video settings (I thought I actually had borderless set). Using borderless now and we'll see how it goes.

Just had a horribly laggy game in places, people with 148 ping running around. This game is going to the dogs.

I noticed that when it lags in the menu, the GPU goes up to like 100% usage. So when I alt+tab even my mouse pointer in windows lags...
I've rebooted the game several times. And the outcome is not always 100% lag but mostly. Once in a while the menu runs just fine. In some cases I do get severe lag but it vanishes after a few seconds and most of the time I get severe lag (not immediately) in the menus but like 1-10 seconds in.
It's annoying as ....
Battlefield is the only game out of all the games I have in my library (600+) so it's obviously a bug in the game. I guess I'm unfortunate to be the very few having it but it's a very annoying bug.

I went back to "fullscreen" in video because if I alt+tab out and back in, the GPU wont fry anymore....
What in the chatgpt is this game code?