What is going on with Grimes?

I'm peripherally aware of who she is: Canadian born musician. Former partner of Elon Musk. Has children with him.

Recently I've observed that a bunch of people I know have been commenting on here, including ones I'd never expect (an Irish ambient musician I've known for 15 years who -- in the man's own words -- cares fuck-all about pop music). I looked in the Grimes subreddit as well as this one and found very little useful info. I refuse to wade through Xitter to look for anything useful. Apparently she performed at Coachella and it went poorly? Can someone elaborate on what happened and why there's such a row over it?