first layer issues - too high & too low issue over print area

I got issues with the first layer being too high & too low in different areas of the bed. Mesh seems to be alright, however looking at the prints it looks like there's no adjustment done on z while printing.
Is there any setting in klipper (probably superslicer) which would disable the adjustment?
So far I upgraded to RatOS 2.0, tried with adaptive levelling and increased number of mesh points, but still keep getting the same results on first layers.
Any ideas?