I have my own story to share, on the bright side this person led to me understanding that the trans movement was a farce and kept me from ever being dumb enough to think I myself could've been trans and led to me accepting myself as the dorky and awkward person I am today
My very best friend, and only person who I ever truly connected to off the internet while in high school, decided to come out as trans (FtM) when we were 14. She started hanging out with a group of people on Deviantart where the one girl came out as trans, and then her online boyfriend (who was 4 years older than her) came out as 'gay'. Only a week or so after these two came out she came out as trans and started socially transitioning. Her take on socially transitioning? Suddenly started drawing a lot of porn, stopped showering, cut her hair kind of short, and started wearing more t-shirts and complaining about her boobs. Up until this point she'd given no signs of being uncomfortable with her body beyond the normal 'I wish my stomach was flatter' type stuff.
At first I respected her decision, adopted her new pronouns of he/him, and referred to her by her name (that she got from South Park lmfao). I was confused, but I was a strong 'ally' to the LGBT+ community and just wanted to be as good a friend and supporter as I could. Then her mental health started to deteriorate, and she started lying online about a host of mental illnesses picked up from her online friends. Started claiming she was bipolar, then switched to that anxiety disorder where you have panic attacks a lot, claimed to be otherkin, then it was schizophrenia, then schizoaffective, depression, started lying online saying she cut herself (she didn't at the time), just a whole bunch of crazy labels while never going to the doctor or a therapist or anything. She started lying about stuff that was happening in her real life, like claims she was being jumped by classmates in the boy's bathroom (only me and one other person irl knew she was trans, and she didn't use the boy's bathroom), claims of being sexually assaulted by her mentally retarded cousin, sexually assaulted by random boys in school, etc. Just a lot of bullshit.
Then she started consuming MASSIVE amounts of porn. Feral porn, Pokemon porn, My Little Pony porn, MineCraft porn, just got really weird REALLY fast. Fast forward two years and her narcissistic behavior and constant lying was starting to get to me, she started whining about how I shouldn't talk about my problems because being tRaNs meant she was soooooo oppressed and had it so hard, she dropped out of school because of the 'bullying', and turned to drawing furry porn and e-rping with her much older boyfriend. She always needed me to compliment how 'manly' she was, or she'd have a meltdown and say I was transphobic or something similar. At one point something bad happened to me, and I vented about it to her, and she turned it into her own story- that was the final straw for me, I blocked her, and said that she was a shit friend and I wanted nothing to do with her.
On the bright side, she is now fat and I would not have sex with her.
For the longest time I thought something was wrong with me for not seeing her as trans but rather influenced by some very horrible people online, but the more FtMs I met, the more I realized they were all groomed into it and had really weird ideas on what being a man was, and all of them were chronic liars with way too much free time. I'm still a little sad that I lost her as I truly did care and love her at one point, but I'm glad she's no longer part of my life and I don't have to deal with someone who needs my constant praise and asskissing 24/7.