More specifically a bug has been reported by numerous players. This bug seems to make your existing Badass tokens disappear completely — meaning that the players whose totals have dropped can’t re-earn those lost tokens. Items and upgrades purchased with badass tokens are also vanishing, without returning the tokens to the players’ totals.
This bug has been reported by all players playing on PCs and consoles as evident by the post on the official forums.
Gearbox has confirmed they are looking into the bug and working for its fix.
Meanwhile, you can see the bug in action down below: