In documents obtained by U.S. website The Blast, Rob, 31, states that he "can no longer afford" to pay his ex $20,000 (£15,500) per month for the upkeep of their two-year-old daughter Dream as he has curtailed his reality TV appearances.
He blames Chyna, real name Angela Renee White, for his reduced circumstances - claiming her decision to file a restraining order against him after he posted explicit pictures of her online last year (17) forced him to stop appearing on his family's show "Keeping Up with the Kardashians".
"Her request was widely publicized and I was scrutinized by the media," his filing reads. "It has been an extraordinarily difficult time for me emotionally and I have no desire to continue participating in the reality show."
According to the documents, Rob was in theory guaranteed $1 million (£776,000) a year for participating in the show, but in 2018 he has only been paid $50,000 (£39,000) per episode for the two episodes he has appeared in. He claims to be taking time out to recover "emotionally" following their acrimonious 2017 split and to have a reduced income of only $10,000 (£7,760) a month.
Rob and Chyna, 30, share custody of Dream equally, and the reclusive reality star claims his ex should now be paying him child support due to her success as a model and businesswoman. Financial records reportedly show Chyna is making around $60,000 ($46,500) per month and is worth an estimated $1.4 million (£1.1 million). He is requesting $2,864 (£2,220) per month from her, but she is fighting any changes to their child support arrangements.
A judge presiding over the case has suspended payments until the former couple resolve their dispute. They are due to meet with the court official in December to thrash out a solution.
Dream turned two on Saturday, November 10, and received touching messages of love from her mum, her aunt Kim Kardashian, and her grandmother Kris Jenner, with the Kardashian family matriarch calling her, "the most beautiful, sweet, kind-hearted and loving little girl."