Trista Sutter in 'Bachelorette' Didn't “Miss”, She Was Just Filming a New Show

ICYMI… fans of the very first “Bachelorette” were thrown into a tizzy when Trista's husband, Ryan Sutterposted a cryptic message on social media saying she went missing on Mother's Day… playing very coy about her whereabouts.

Trista finally resurfaced online, reuniting with his family in Mexico and giving an equally vague message about his mysterious disappearance. It was all weird — but now TMZ has learned exactly what was behind it.

Sources with direct knowledge tell us…the reality TV legend wasn't “missing” after all — instead, we're told she was filming season 3 of “Special Forces: World's Toughest Test” from Fox.

For those unfamiliar with the series, “Special Forces” takes a group of celebrities and puts them through grueling challenges from the U.S. Army selection process.

The series has become an opportunity for celebrities to challenge themselves while putting their physical and mental strength to the test… with the “Vanderpump Rules” star Tom Sandoval“Bachelor” veterinarian Nick Viall and “Dance Moms” alumnus JoJo Siwa everyone tried in season 2.

This explains why Trista said she experienced a lot of personal growth and a journey when she resurfaced – and Ryan also played a part in that with his publication on social networkswhich was obviously carefully designed to conceal the casting news.

BTW… “Special Forces” goes deep with Bachelor Nation, as our sources also say Ali Mannoformerly Fedotowsky, will also be present this coming season.

Fans of this “Bachelorette” alum, from Season 6 in 2010, may have noticed that she's been posting a lot of intense workouts in recent months, including boxing, weightlifting and cold dives. So now we know why she was getting so physical.