The comic/actress was performing at the Dania Improv in Florida earlier this week, when she appeared to address Katt's fresh round of hate aimed at her, Kevin Hart and many, many others in the game ... and she clarified a claim he made about her to Shannon Sharpe.

Long story short ... Katt said that a recent doc made about the famous Comedy Store club in L.A. had suggested that several Black comedians -- including Tiff -- had performed there over the years, but KW insisted that simply wasn't true and that she'd never gotten onstage there.

Welp, Tiffany had something to say about that during her Thursday set ... when she rattled off a lot of shows and movies she'd been in, and how long she's been honing her craft.

Eventually, she tackles his allegation that she'd never open mic'd at the Comedy Store -- at least not while coming up, anyway -- and TH refuted that ... saying she had, but just on the "white nights." The flip side ... Tiff says she definitely performed on all the "Black nights."

Mind you, Tiffany had already fired away in the comment section of a clip of Katt's interview where she got mentioned ... and there too she suggested KW didn't have his facts straight.

It's also worth mentioning ... Katt's been feuding with Tiff (and her close friend, Kevin Hart) for years now -- and he infamously trash-talked her and her comedy chops on a radio show.