Compound path bugs
Have had situations where compound paths untether an object from layers, so it basically has no home. When reloading the app all of the progress is gone. I have no screenshots because everything disappeared.
Many design-breaking bugs can be found by doing basic Illustrator stuff, I rarely have a file come out unruined if I decide to work on the iPad. It’s a shame because I enjoy how it feels on iPad, but it doesn’t work and they haven’t fixed common file-breaking bugs that have been around for years.