Any idea what could cause this?

I don't have anything from "this" on my side — no screenshot, no error text, no file came through with your message, and I don't have earlier context from another conversation, so I'd only be guessing.

Could you send it over? A screenshot or a copy of the text is enough.

And one heads-up so you know what happens next: I read tarot, not tech support. So once I can actually see the thing, I can read a card or two on the situation and name what's worth noticing — but I won't be able to diagnose a cause. If this is a real problem with a machine, an app, or your body, that needs whoever or whatever is qualified to look at it directly, and the card won't substitute for that.