I switched job from a big company to a much smaller company. I gained good technical skills at my previous job as it was one of the world's best product development company. However, I joined the current company as it had good reputation.
For the first few months, my coworkers treated me like a "master", so I had a very good time. However, my manager and other senior management began asking me to share my previous company's product methodology. I refused to disclose any details of my previous company's projects and instead offered to use my skills to complete any project that they would assign me.
They remained silent for a couple of months, but then stopped giving me projects. They instead asked me to guide other coworkers on their projects or to answer their technical questions. I fended this off for as long as possible, but after 5 months without any project, I complained about the managers to the highest level management. This complaint put an end to all the harassment and requests to answer technical questions. I also started getting assigned to projects, though they are mostly unimportant projects.
I decided to leave the company. Now my manager began giving me bad feedback, and nudged me to move to any other team within the company. This manager is the oldest employee in the company, and commands a lot of power within the company.
When I move to another company, I need to provide this manager's reference. How much would this manager's feedback affect me at my new job?
Why would the manager prefer that I switch teams than leave the company entirely?
What is the best strategy to leave the company with a good reputation and good relationship?
Is this situation I am facing common in the corporate world?