As a bisexual human, I like almost anything when consuming the pornography. But I can never find good bi content. It’s always some video that’s 20 years old and so over produced and acted that it’s awful to watch. But you can’t find any decent modern content with bi themes. Or its a gay/lesbian video wearing a cheap mask.
Have you looked into alternative production companies? Erika Lust is my go-to for queer, feminist, equality-focused, fair porn. They have some stuff that’s specifically catered to bisexuals, too. Try it out
Similarly some independent creators will do it every so often. Usually you’ll see some push back in the comments though because it’s not their usual straight or bi-girl content