AITA for quitting suddenly after being put on a PIP and now feeling like my ex-boss hates me?

I (late 20s) recently left a job after a year and 3 months. For the first 6–7 months, things were going smoothly. I had a trainer I got along with and was progressing well. Then I got assigned a new trainer who was... different. She often treated our training sessions like therapy, venting about her daughter being bullied, her family life, and other personal stuff. I tried to be polite and empathetic, but it took up a lot of time and focus.

I was still technically in training and hadn’t been officially signed off on any responsibilities. I was also working off just a laptop while waiting on a monitor, which made things more difficult.

About 14 months into the role, I was suddenly put on a Performance Improvement Plan (PIP). I had 4 weeks to turn things around. I asked my manager to switch trainers, but he refused. Meanwhile, my trainer allegedly told another trainer and my boss that I came off “defensive” in emails. When I confronted her about this, she denied it, but acted evasively.

A week into the PIP, I decided to quit. I brought my stuff into the office Monday morning and handed in my resignation. My manager called me saying he felt blindsided and asked me to take a day before deciding, but I told him his email about the PIP made things clear.

Since then, coworkers have deleted me off LinkedIn. My former manager didn’t acknowledge my new job announcement at a major bank, even though I’ve seen him congratulate others. While I was working there, he’d occasionally joke about firing me, but I brushed it off at the time since there hadn’t been issues with my initial performance.

Now I’m wondering… AITA for how I left? Or is there something else going on here? I can’t shake the feeling my ex-boss resents me.