I've worked in Germany for 3 years with the same employer/title. I had an EU blue card for 15 months when I was first here then lost it when I renewed my permit (after an increase in income eligibility threshold which I no longer met). If I change jobs to a new employer, and qualify for the card again, does the past period count towards the permanent residence, i.e. Niederlassungserlaubnis , eligibility period (33 months or 21 months with a B level German)? Or do I have to start all over again (at which point it no longer matters because I would be automatically eligible for the permanent residency if I've been working in Germany for 5 years).
I've already asked at the local ausländerbehörde, but they always seem to so confused with my questions and can't give direct answers.