Let's insert a bit of adult into the Vesper situation:
Unless something else comes out, it's pretty safe to assume that the issue was Vesper turning off the monetization after being told not to and then he turned it off again. With the new Axel stuff, he probably also reacted badly when told, again, not to do it.
For a moment, take off your default "corpo bad" hat and think about it:
HoloStars was not doing well and when they finally decide to gamble on an EN branch they finally strike gold, but then one of their most popular new talents decides that he doesn't want the monetization which is where Cover takes their cut from. If their contracts are similar to whats known from HoloLive, he will still get payment from Cover though, it's only Cover the ones that won't get shit.
I can understand the initial "shock" from receiving so much money when you pretty much "won the lottery", but it's pretty cringe and juvenile to still be going about that after and actually take action to not get paid and fail your obligations.
I don't think Vesper is being malicious or even thinking about it, but he is honestly behaving like a 20 year old kid when the dude is 3x, pushing 40.