"Sofia isn’t happy that Scott was photographed out with Bella," a source told Us Weekly. "They are both trying to move on and do their own things, but it's been somewhat difficult."
"Kourtney is sort of ignoring Scott being out with Bella, for now," the insider noted. "She knows that sometimes he can be all over the place. But as long as he continues to still be a good dad, that's all she cares about."
Kardashian also has a soft spot for Richie. The source added that she "feels for Sofia because Scott put her through hell and she knows how he can be and how tough the situation can be."
Disick was seen leaving Nobu in Malibu with Banos on October 1. The 37-year-old reality star and the 24-year-old model were first linked in 2017 after he was caught with a woman in a hotel room during their vacation in Costa Rica.
Disick and Richie decided to call it quits over the summer after being together for three years. The pair reconciled for a brieft period of time but ultimately went their separate ways in August. Their split was followed by Disick being in rehab for some time, seeking treatment for his past traumas.
Disick shares children Mason, 10, Penelope, 8, and Reign, 5, with Kardashian. The two dated on and off from 2006 to 2015.
Disick, meanwhile, has been struggling with health conditions and has been diagnosed with low testosterone levels — something that he blames his party lifestyle for.
"All of the beatings that my body took over the years of drinking and partying and running around, my body can't be perfect," he said in the recently aired episode of Keeping Up With the Kardashians. "So obviously I don't drink anymore, but my body still has things in it, even from taking sleeping medications, doctor-prescribed medications. And then when I got my blood results in, my testosterone was so dramatically low, they were like, concerned how I even have the energy to get out of bed every day."