Yeah just another visual bug, all you gotta do is get a lot of upgrade points and then spam them and because of that I found this accidentally. Yes, this is purely visual, and you can’t get endless upgrades from it. To be honest though, I think this should be a feature in game. Always being able to see your upgrades is really helpful
How it usually is (if you don't think this is a bug)
With upgrade available
Without upgrade available