Don’t worry, I watched wandavision and still have no idea why the hell she was like that in MoM. It was extremely clear the writers of WV and MoM never once talked to each other, despite one being a somewhat continuation of the other.
MoM left such a bad taste in my mouth after being the only Phase 5(?) movie I was even remotely interested in that I haven’t bothered going to the theaters for anything marvel since.