Why my 2D shadows have low resolution?

Dear Unity community. I'm using Unity's URP(version ) 2D lights and shadows. Before i used Unity 2019.3 and everything looked great, but then I've upgraded to Unity 2021.1 and I've noticed my problem:

• When is resolution in game window set to Full HD my shadows look very pixelized (definitely not Full

• The rest of the game looks fine

• When I set resolution to QHD/ 4K they become crisp and nice(trough the fact that my display is only Full HD)

• But i can't get this resolutions in build because my display doesn't support them

• I've tried different light/shadows/quality settings but nothing seemed to help.

• In Unity 2019.3 was everything ok

• In game window is it noticeable but if maximized or in build it is unmissable

• Please maximize pictures to see what I mean
  Do You have any ideas how to make my shadows look better?
  Thank you very much for response!