Monica is clamming up when it comes to questions about her divorce with ex-NBA baller Shannon Brown ... and it's pissing off producers on T.I.'s reality show.
Sources close to production on "T.I. & Tiny: Friends & Family Hustle" tell TMZ ... Monica is refusing to talk about calling it quits on her marriage, and she won't even mention her ex-husband's name.
We're told Monica's decision to stay mum is frustrating the people tasked with crafting an interesting storyline for the singer ... and she's just not cooperating with producers begging for her to open up about her relationship with Shannon.