Hi! Since yesterday I'm having an issue with my Macbook Air Early 2015 with BigSur: it shuts down unexepectly. I can't work more than 2 minutes with it. I tried resetting the SMC. I also changed the battery last year. When I run the log in the terminal (as explained in other forums and pages) it says "previous shutdown cause 0"; I've read and this code is for power problems (battery damage or drivers problems). Do you know what it could be? Thank you very much.