EXCLUSIVE

6:40 P.M. PDT -- Porsha tells TMZ ... she was "blindsided" by her demotion ... saying she's only capable of being herself because "portraying anything else, would not be genuine nor honest." And while she's happy to still have a role on the RHOA ... she'll focus on her career and a new love.



Porsha Williams was demoted to being a "friend" on the upcoming season of "Real Housewives of Atlanta" after filming had begun ... because producers once again got fed up with her behavior.

According to our sources, Bravo had intended Williams to be a main castmember this season ... even after her monumental fight with Kenya Moore.

But when filming began, we're told Bravo tried to get Williams and Moore to talk things out, but Williams nearly fought her again. Our sources say Williams also went after new castmember Claudia Jordan.

Temper issues aside, we're told Williams also kept the show at arm's length and wouldn't reveal certain details of her personal life ... leaving producers with no story to tell.