1) Yes, you clearly do have a problem with trans girls if your response to finding one attractive is to say, "Are you fucking with me?" followed by a night of binge drinking.

2) WTF does gaydar have to do with trans people? Yeah, they're lumped together in the "LGBTQIA+" label, but they're totally different things. That's like thinking you can cook beef when you've only ever made chicken, but it's okay because they're both animals.

3) Everyone who says they can absolutely is not able to "always tell", you're just only clocking the ones who aren't passing, often because they started transitioning at, like, 35 instead of pre-puberty. I've seen transvestigators literally get fooled by a picture of Sigourney Weaver, one of the most recognizable cis women on Earth. If they looked at Trace Lysette, they'd swear up and down she was cis.