I reset my switch and now I can't download 3d All stars anymore even though i bought it in january or february. Is there a way to fix that? Thanks in advice

Are you using the same Nintendo account you were before you reset the system?

yes

If you're using the same Nintendo account, open the EShop and go to the top right corner where your profile is, there should be a re-download section there. You should find 3D All Stars there.

Thank you very much it worked!