Does kernels downgrading cause problems

I have downgraded form the 6.1 to the 5.15 LTS kernel and i was wondering if that would cause any problems with my system?

Note: I first downgraded and then i installed my video-nvidia drivers

You mean you installed a second kernel and can now use this one as well as the one that was pre-installed.

Why not just boot it and try?

Worst case is it will not work.

Keep the other kernel so you have something that you know will work - you can have two or more.

i am using the 5.15 kernel right now and so far nothing visibly wrong has happened
I am more worried about things under the hood, not noticeable by day to day use

short answer:
don’t :sunglasses:

start solving problems when they occur

ok will, thanks

5.15 is a long-term-support kernel, so it continues receiving security updates and bug fixes. Unless you have bleeding-edge hardware that requires support only available in the 6.x mainline kernel series, LTS kernels are the recommended choice.