What would cause a person to speak in different accents randomly?

There’s this woman I work with who seems to have her accent change randomly.

Some days she sounds like a typical American accent, then others she sounds like she has a Caribbean accent and others she sounds like she has a French accent, and others she sounds like she has an Arabic accent. Other days her voice is super messed up, like she’s been screaming.

Beyond her voice changing, she is an odd person to work with. She’s gotten into public, loud vocal spats with other coworkers even in meetings. She was very nice and sweet with me when I first had to interact with her but that all changed when I made an honest mistake one time and she went off on me and wouldn’t stop until I ignored her and now I just keep my distance unless I have to. Others have said similar things about her as well.

I’ve wondered if maybe she has a personality disorder, but I would think that would also cause her to not do her job correctly?

I don’t know, I’m just curious. This is something I’ve never experienced before and wondering what this could be.