incorrectly baked lighs

Hi Guys
in case that there are more lights in the scene, I get strange baked lights results (incorrect “grainy” shadows - see attached image). I’ve tried to use different settings but it seems that it does not have the effect.

The screenshot with incorrect results and light settings is here: (+attached)

thanks for help in advance

Update: “Generate lightmap UV” under “model” tab has to be checked when importing asset. It helps in 99% of situations.

It doesn’t if you hand author your lightmap UVs.

See answer above.