Matt Brown, one of the stars of Discovery’s “Alaskan Bush People,” allegedly spiraled during a disturbing YouTube livestream recently … and now members of his family tell us this is exactly the kind of behavior that led them to distance themselves from him years ago.

Matt appeared nude and allegedly intoxicated while wandering through a public park in Washington state Tuesday, livestreaming himself as he rambled incoherently around town. At one point, he appears to be carrying a gun while continuing to broadcast live to viewers.

Now, family sources tell TMZ … most of the Brown family cut ties with Matt roughly five years ago after late patriarch Billy Brown ultimately decided the family could no longer support him because of his ongoing alleged struggles. Matt has been public about his battle with alcohol issues.

Our sources say the family had serious concerns about Matt’s behavior long before Billy’s death in 2021 and viewed separating from him as necessary for both their safety and the family’s image.

We’re told Gabe Brown is currently the only family member who occasionally still communicates with Matt … though our sources describe their contact as rare.

Matt’s alleged alcohol issues have long been documented publicly and were also widely known within both the Brown family and their Alaska community. According to our sources, relatives viewed Matt as “too toxic” to remain closely associated with the “Alaskan Bush People” brand.

Our sources claim family members are especially fearful of Matt when he drinks … describing him as a “functional drunk” capable of spiraling into paranoia and dark thoughts.

As fans of the show know … Matt stepped away from “Alaskan Bush People” in 2019 after entering a treatment facility to address his issues.

After rehab, Matt relocated to rural northeastern Washington, where he largely stayed out of the spotlight while building a following on YouTube through livestreams and personal videos documenting his life.