People.com Entertainment TV Maks Chmerkovskiy and Vanessa Lachey Are Back in the 'DWTS' Studio After Chemistry Controversy Sources told PEOPLE that the Chmerkovskiy, 37, and Lachey, 36, have been "bickering" since the beginning of the competition By Karen Mizoguchi and Abby Stern Published on October 5, 2017 01:53 AM Share Tweet Pin Email Maksim Chmerkovskiy and Vanessa Lachey were back in the rehearsal studio on Wednesday after Chmerkovskiy missed this week’s episode of Dancing with the Stars. “Maks is back. We saw him and Vanessa today in the studio. They’re excited to be together again,” season 25 pro Lindsay Arnold said at PEOPLE’s Ones to Watch Party presented by Maybelline New York at NeueHouse in Los Angeles. Co-host Erin Andrews informed viewers Monday that Chmerkovskiy’s absence was due to “a personal issue,” but sources told PEOPLE that the DWTS pro, 37, and Lachey, 36, have been “bickering” since the beginning of the competition and he chose to sit out from rehearsals and the live show due to a clash between their “big personalities.” Rob Latour/REX/Shutterstock “Honestly, they’re awesome, I love them. Nick and Vanessa are awesome so are Peta and Maks. They’re such a fun partnership,” said Sasha Pieterse, who is currently competing on the ABC dancing competition with pro Gleb Savchenko. RELATED GALLERY: Introducing PEOPLE’s Ones to Watch 2017: Rising Stars You Need to Know Craig Sjodin via Getty “I don’t know what’s going on but all I know is that he had a personal issue, a family issue. Alan was great and now [Maks and Vanessa] are reunited,” the Pretty Little Liars alum, 21, added. Rob Latour/REX/Shutterstock Chmerkovskiy took to Twitter Wednesday to apologize to Lachey for his absence, which left his partner to perform with first-time pro Alan Bersten. “As you are all aware, I had to leave the show last week to take care of some personal issues. I take full responsibility for my absence. And want to apologize to my partner Vanessa. We are both looking forward to dancing for our fans next week!” the father of one wrote. Frazer Harrison/Getty Images FROM PEN: Inside DWTS’ Mark Ballas and BC Jean’s ‘Timeless Bohemian’ Wedding – Complete with Drum Circle! The dances for week 4 will commemorate the celebrity contestants’ most memorable year. “I think we all are genuinely excited about this next week,” said Arnold, who was accompanied by partner Jordan Fisher. “It’s huge and every celebrity is opening up about personal things that are in each of their lives. The vibe is awesome,” Arnold concluded. Dancing with the Stars airs Mondays (8 p.m. ET) on ABC.