https://www.thelist.com/1518477/inside-reported-rift-between-bea-arthur-betty-white-golden-girls/

Bea Arthur and Betty White disagreed on many things behind the scenes of "The Golden Girls," but when the cameras rolled, they were total professionals.

They were true professionals. There was one episode that rubbed Bea the wrong way that really made things boil over. During one of the bloopers in front of the studio audience, Betty made a joke about Bea flubbing a line. The audience laughed because it was a funny, light hearted moment. Backstage Bea flew into a rage and called Betty the "C" word.
You would never know this friction existed because they jelled so well on camera. Betty was a trooper too because she never let it get to her and she never held a grudge against Bea.