Sources with direct knowledge tell TMZ ... one of the lingering issues in the wake of the divorce stems from holdings related to the 'Magic Mike' franchise, which they built together during their marriage.

Remember, Jenna helped Channing find a choreographer for the live 'Magic Mike' shows, and she moved to London to support their family when he was in production across the pond.

Our sources say Channing and Jenna have been unable to agree on how to split the assets from 'Magic Mike' ... we're told they were recently in intense mediation over percentages, but couldn't strike a deal.

Channing has turned 'Magic Mike' into a hugely successful business, with the movie, live shows and an upcoming reality show ... and our sources say there's a lot to sort out.

According to new legal docs, obtained by TMZ, Jenna is requesting a trial in their divorce case to settle a number of issues, including a property settlement and spousal support. Jenna is currently engaged and recently had a baby with Steve Kazee.

Our sources say Channing and Jenna are in agreement about one thing ... the best path forward is to let the court step in and settle things once and for all.

We reached out to reps for both ... so far, no word back.