Any idea what can cause the cursor to suddenly dissappear? It's the only issue I currently have with wezterm, an otherwise fantastic terminal emulator

Many, many interactive programs.

Programs that draw a progressbar often hide the cursor so there won't be a blinking cursor "glitching" the visuals. Once you see it, you'll start noticing programs that hide the cursor.

If it happens only on wezterm, it is probably some kind of bug on their part (no support for the escape code that re-enables the cursor maybe?). Have you tried other terminals?