After years of hiding out in sister Khloe's home, battling depression and Diabetes, a happy and healthy Rob Kardashian finally returned to the spotlight and began filming a spinoff series with pregnant fiancée Blac Chyna.
But now, it seems the overweight father-to-be, 29, has retreated into isolation, putting the future of his show in jeopardy, RadarOnline.com can exclusively reveal.
"Rob has refused to film for weeks," an insider tells RadarOnline.com.
According to the source, Rob is worried that the production is ruining his already volatile relationship with Chyna, 28.
If he continues to act up, the insider insists, his show will be cancelled.
"You can't make Rob do anything. He isn't worried about contracts, and it's become a waste of time for everyone."
He even made a vulgar sexual remark to his own mother, Kris, in a video posted to sister Kourtney's Snapchat.
The E! series, tentatively called Rob & Chyna, was set to air later this year.