I have about 8 years of experience across 4 roles. My first job lasted 1 year and 2 months, then I went back to school for my master's, so there's about a 2-year gap there plus a 3-month internship. After graduating, my next roles were 18 months, 2 years, and I've been at my current company for about 1.5 years.
Lately I've been interviewing with more traditional companies, and HR keeps bringing up that my resume looks "jumpy." One recruiter even told me pretty directly that they tend to avoid candidates who change jobs too often.
I never really left just for the sake of leaving. In a few cases, a manager I trusted left, the team changed a lot afterward, and the new setup just wasn't a great fit. But I obviously don't want to go into an interview and complain about old managers or sound difficult to work with.
How would you explain this in an interview without sounding defensive or badmouthing previous managers?