I just had two grapevines complete for the first time that yielded grapes with no qualities. I had harvested some earlier today from another farm that had all their qualities (but these were older ones that I knew were good) The only thing I can think of that I did which could've affected it was moving a beehive that no longer covered them in its radius. They were also planted against my stone mansion but other plants like peas didn't have this quality issue.
Here's a screenshot:
