I was leaving told the hiring manager they couldn’t let me go for 3-6 months.
Lucky for me the hiring manager ignored them and took me in 2 weeks. What exactly did they think I was going to do for 3 months knowing they were delaying a big promotion for me while forcing me to do a job I was trying to leave?
The manager I left was vindictive and tried to say he had some input for my performance review that year, 7 months after I left. My new manager forwarded it to HR and blew the whistle on it.
I got a new job and a fat raise. My old manager was demoted to no longer manage people. 4 or 5 years later he applied for a job in my org and I was part of the interview team.