A source tells PEOPLE that Tyga tends to distract Jenner from her work and other commitments

Kylie Jenner and Tyga‘s relationship has been full of ups and downs, but is the couple on the edge of a breaking point?

A source close to the famous family tells PEOPLE that the 19-year-old Keeping Up with the Kardashians star and her rapper beau, who are currently on one of multiple breaks in their nearly three years of dating, have a “complicated” relationship.

“When Kylie is happy, they’re happy — but it’s never that simple,” the insider says. “There’s always some kind of drama with Kylie and Tyga.”

According to the source, Tyga, 27, tends to distract the makeup mogul from her work and other commitments.

“When he’s around, that’s all that matters in her world,” says the source.

“And she’s in such an incredible position right now — poised to have such incredible success,” says the source of Jenner, who will be starring in her very own KUWTK spinoff this summer, Life of Kylie. “But when things go awry between those two, Kylie loses focus and turns into a different person. She won’t listen to anyone — it’s like nobody can talk sense into her until they work things out.”

“If they could ever get to a mature point where it was more of a functional relationship, things would be amazing,” adds the insider. “But until then, it continues to be a sore subject.”

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Multiple sources confirmed to PEOPLE earlier this month that Jenner and Tyga are currently taking a break from their on-again, off-again romance.

“They tend to take little breaks all the time and then get back together,” a source previously told PEOPLE. “It’s definitely possible they’ll work things out again.”

Despite spending time apart, Jenner hasn’t been completely distant: She recently shared videos of herself lip-synching to Tyga’s new songs “Act Ghetto” and “100s,” which he premiered on Soundcloud, and has also been actively liking the rapper’s posts on Instagram.

The duo were first linked in the fall of 2014, though they didn’t confirm the relationship until March 2015. Following Jenner’s 18th birthday in August that year, the two became much more open as a couple, regularly stepping out together and documenting much of their love on social media.

On Tuesday night, Tyga was detained by LAPD officers after leaving a Hollywood nightclub for driving with paper plates in his new Mercedes G-wagon. He was loaded into a squad car and taken away to the police station to perform a field sobriety test due to the number of paparazzi at the scene.

“He passed the field sobriety test and was released,” Officer Liliana Preciado of the LAPD Hollywood Division told PEOPLE. “He was cited for a minor traffic violation.”

Keeping Up with the Kardashians airs Sundays (9 p.m. ET) on E!