New job

I'm starting a new np job I left my last one even though I had excellent performance reports it was felt I was not a good fit. My supervising md had nothing but praise for me and my Ability ,and expertise none of that was taken into account when it was decided I was not a good fit,no explanation was given as too not being a good fit. I do know that after my hire I started having cardiovascular issues and was told I needed to give 8 weeks notice for a sick day to have my testing . I'm excited to go back to work but nervous