The clip, shot by a witness on May 17, 2023, shows Blake outside a Hoboken, NJ restaurant, looking visibly annoyed at Justin ... who we're told was directing, not acting in that particular scene with her.

It could've been creative differences or just a miscommunication ... but the clip seems to show them in the thick of some on-set drama.

One source, who was on the set, tells TMZ ... Blake and Justin were not upset with each other, and there's no drama that day -- they were in between takes, and simply talking.

At the end of the clip they're still standing near each other, so it's not like anyone stormed off.

Now, a witness, who was not involved with the production, says Blake was often spotted in the area during filming, and rarely looked thrilled.

Then again ... the film's plot about domestic violence could also be a reason she didn't look too happy.

Speculation about the pair's feud has been brewing online since Justin passed on taking group pics with Blake and other cast members earlier this month during the NYC premiere. Instead, he posed only with his wife.

He’s since been flying solo on the promo circuit, even hinting at dealing with "complex personalities."

Meanwhile, internet sleuths discovered both Blake and Colleen Hoover -- whose book inspired the movie -- have both unfollowed Baldoni on IG.

All the real-life drama isn't hurting the movie at the box office. It debuted on Friday and took the second spot for the weekend, right behind Blake's hubby Ryan Reynolds' "Deadpool & Wolverine."