I think some of these may be internal issues with the StickyKit library we use. Unfortunately, we need functionality beyond the standard position: sticky CSS, so we do need custom JS. I suspect in the future, we may be able to ditch the library and use some more modern browser features (position sticky and intersection observers, I think) to achieve this effect in such a way that hopefully doesn't trigger issues like this. However, given that it seems to happen quite infrequently and it probably does need a whole new approach to fix, I'm not sure we're likely to focus on this for a while. Short of just closing this as a "won't fix" after all this time, I think I'll move it to future fix.