I saw this one in perspective, maybe applies to vison too, where I bound to an expression with if statememt containing {view.custon.propname} with a typo in custom, and the quality returned was bad stale which took a few hours to finally realise it was just a typo... The prop name itself was bound to a tag, so I was chasing a ghost trying to find an issue with the tag. This quality was extremely deceptive