The Brief: To switch up means to change one's mood, attitude, personality, or state of mind.

DEEP DIVE
People might switch up on their friends, or partners, particularly if they’re in a fight. It can also mean to leave or give up on someone.
I’ma have to switch, switch up on you –Nicki Minaj, “Nip Tuck”
https://twitter.com/ryleepitre/status/1029220597073682432