This is not true. IIRC this factoid comes from the results of surveys asking people whether they had ever been the victims of domestic violence (not necessarily in their current relationships), and it should come as no surprise that relationships comprised of two women have the highest reporting rates of having been subjected to violence over their lifetimes, and relationships of two men the lowest rates. Within-relationship rates of domestic violence for lesbian couples are not higher than for heterosexual couples!

The above stats actually align with the divorce rate:

https://www.them.us/story/lesbian-marriages-weddings-divorce...

Wow, that's really torturing the data to fit your worldview.