I've encountered cases where a parameter tooltip for a function is active (for a function with multiple definitions), a list pops up and pressing cursor keys does not navigate in the list but cycles through the definitions in the tooltip.
Obviously, the bugs that appear rarely and inconsistently are difficult to track. We suspect the ones you report here are related to some timing issues with the IDE and VA X.
If you don't mind, take a screen shot when an odd assortment of tips and listboxes appears. We might discern some clues to the solve the problems.
We do solve problems we encounter, at least we make decent attempts at it.