First off: this is not the Steam thing. I know very well about that and that it isn’t a bug. This is a bit different: my Units displayed as 0, but the actual amount of Units I had seemed to be unaffected. I could play the game normally, and a quick spin of the Spin to Win wheel confirmed that I still had my Units, just not the number. This was a one-time issue, and I do not have this anymore.
My Unit count displays 0, but I still have full access to my inventory.
Despite seeming like I have no Units, I can still pay for a Spin to Win spin. And no, I didn’t win anything nice.