Try to using FN + up/down key(F2/F3) to adjust the brightness.

That has been the issue all along. Neither the function method or the screen brightness settings work. The screen stays %100 all of the time.

Had the same issue since I updated to 31.0.15.2879, A08 released 10 April 2023 although this is officially released by Dell.

To get the function back you can downgrade to 30.0.15.1272, A07 released 13 June 2022. Although this is 10 months old this is the newest "previous" update officially released by Dell and will get your brightness setting back.

Rolling back the drivers won't work. I use software that will not rum properly on the older versions.

The only other solution i know of - besides rolling the driver back to 522.25 - is to disable Optimus in BIOS, the battery will still drain faster due to this though.

I have the same problem. Did you find the solution except downgrading driver?

No, I have not found a solution, nor do I think Dell even cares to fix the issue. I have seen others post about having the issue and it seems like the only answer that is given is to roll the drivers back...which is totally unacceptable if you plan on using any software that is dependent on current Nvidia drivers.

Can't believe I need to use year old drivers in order to control brightness.

Same issue for a year... I am continuously looking for solutions but it seems that the only way until now is downgrading drivers. But as many people think that is unacceptable.

Meanwhile, I program the brightness at a comfortable level (20% in my case) and reboot my computer. I  don't know why but when it restarts brightness is at the programmed level. If you required more brightness just program at a higher level and reboot.

Is not the best solution but at least my eyes and battery will thank me.

That is a new workaround that I was unaware of. I guess it will have to do, since Dell obviously has no interest in fixing the issue. Sadly this will weigh heavily on my next laptop purchase.