Kim Zolciak and Kroy Biermann's Fighting Started Last Week, Argued Finances

The newfound happy times between Kim Zolciak and Kroy Biermann were very short-lived, in fact, just a few days after celebrating their 12th anniversary, they were at each other's throats ... TMZ has learned.

Sources familiar with the situation tell TMZ it's been about a week now since Kim and Kroy started having issues in their marriage once again. We're told the fights were intense, per usual, and revolved around their atrocious financial situation, and its impact on their relationship.

Translation: back to the common theme that prompted Kroy to file divorce docs, in the first, and second place.

We're told Kim and Kroy remained under the same roof while they verbally sparred, and things continued to bubble between them.

We're told throughout the latest period of fighting, Kroy remained in the primary bedroom and Kim was in the basement/nanny suite -- as ordered by a judge -- but that distance wasn't enough to keep the peace.

Everything came to a head Monday night when one of the estranged couple's young kids called the cops during an "extremely loud" fight between the two. Law enforcement sources tell us 3 officers and a supervisor came to the home to settle things down, but no one was arrested.

Interestingly enough, Kim and Kroy were seen out with their kids for haircuts and some Starbucks just hours before the police visit, and everything seemed calm.

The drama is 180 degrees from what the couple portrayed on social media when they celebrated their wedding anniversary on November 11 with a fancy meal and drinks ... seemingly oblivious to the massive money woes they continue to face.

Speaking of their financial troubles ... Kim and Kroy's Georgia mansion, which was supposed to go up in a foreclosure auction, is still on the market for $6 million.