There is no beef between them.
Tyrella fans to have been foaming at the mouth since the show ended to drag Whitney. Nothing she says or does is ever good enough for them. They believe that Whitney is jealous of Ella.
I remember seeing a tiktok from Catherine's stories the night they Whit, Ty, Ella and Cat had gone out. Whitney was taking the video and she showed all of them and before going to Cat, she said my heart, a phrase that Catherine uses all the time. Ella fans used that to justify that Whit is a fake friend to Ella.
The fans seem to be competing against each other. Each side buying the Whit and Ella followers in order to seem like the more successful one. Ella fans also started buying Whitney tons and tons of followers in an attempt to accuse her of buying followers so that she can catch up to Ella.
It's really a whole lot delusion and constantly taking everything Whitney says and twisting it to fit a narrative they've already decided on.