"Dancing With the Stars" fans are still confused about what happened to pro dancer Maks Chmerkovskiy.

During last night's Season 25, Week 3 live show, it was revealed that Maks was "dealing with a personal issue" so pro Alan Bersten would step in to dance with Maks' celeb partner Vanessa Lachey.

No further intel was given on the "personal matter," leaving fans to worry that it had something to do with Maks' son with fellow pro Peta Murgatrod. But Peta was still there dancing with Vanessa's husband Nick Lachey, and Maks' brother Val was also there, suggesting it wasn't a Chmerkovskiy family issue.

But now rumors have come out that Maks chose not to dance because he was fighting with Vanessa.

"There's a big chemistry issue," an insider told People. "They both have big personalities and that's not always the best recipe for a good partnership."

Us Weekly also heard from a source -- maybe the same one, considering these sources are all unnamed -- saying the Vanessa/Maks partnership was "not going well" behind-the-scenes. "There is a lot of fighting going on behind the scenes," a source told Us. "They're playing nice for the cameras but both are miserable paired with each other."

Over at E! News, a source said the two "can't find middle ground," which has produced tension. "Their personalities have completely clashed and they really don't get along off set."

That may be the case, but they have worked together up to this point, and they will work together again in Week 4. "Maks and Vanessa are returning to rehearsals and will be dancing together on next week's show," a show spokesperson said.

Both Maks and Vanessa have also mentioned looking forward to getting back to work together:

This coming Monday, Oct. 9 is Most Memorable Year Night, which should allow for Vanessa to tell her own personal story away from all of the rumors and drama. DWTS airs Mondays at 8 p.m. on ABC.

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