Dell XPS 9570 - BIOS version 1.42.0 vs. 1.27.0

The official and last version is 1.27.0. I think it was Windows, but how can I have a 1.42.0 version installed? When I try to downgrade it says it's impossible, but in the BIOS it's checked on yes to downgrade. Can you help me at Dell to put back your version 1.27.0 because I noticed my PC is not working as it should be.