Cardi B Fired Manager for Allegedly Pocketing a Fortune

Cardi B thinks she had every right to drop her ex-manager because she says he was pilfering boatloads of her cash behind her back.

Sources tell us Cardi first confronted her manager, Shaft, on Super Bowl weekend, claiming he essentially cooked the books to make it appear Cardi was pulling in less money that she was actually making, and he was keeping the difference.

Our Cardi sources put it this way ... if Cardi got a gig that paid $100,000, Shaft would tell her she was making $50k and allegedly pocket the balance.

What's more ... Cardi's fiance, Offset, went ballistic when he learned she was paying Shaft a 20% manager's fee ... way more than he says is the norm. Offset pushed her hard to give Shaft the boot, which she did.

TMZ broke the story, Shaft is suing Cardi for $10 million for breach of contract, claiming she had an obligation to keep him on, especially since he was the driving force behind her meteoric rise.

Our Shaft sources say he acknowledges 20% is a high management fee, but he used a lot of the money to pay writers and producers who engineered her music. He thinks Offset was on a mission to sack him just so he could control her and her career.

We've reached out to Cardi and Offset's team for comment ... so far, no word back.