I'm a senior software engineer that has been working in a small/mid-size company for 3 years. Recently, my team of around 20 people was restructured. This lead to my co-worker (the only person on the team that I don't get along great with) being promoted to my manager, and me being moved to a smaller team in which I'm the least senior member. My job title and pay is still the same.
Since then, my work has been more along the lines of a junior/mid-level engineer. I haven't been given any tasks larger than a small feature (or a small part of a larger feature). I also haven't been invited to meetings discussing architecture, new projects, or technical problems. This is at a time when the team has a higher per-person workload than ever before.
At each of my 1:1s since the restructure, I've asked for more responsibilities, ownership of a project, inclusion in technical meetings, etc. Each time my new manager has said she'll get me something good to work on. There's been a fair bit of friction between my new manager and me since I was first hired (when we were co-workers), so I'm not confident she's representing me well to higher management.
I'd like to avoid leaving this job if possible, because the pay is far above market rate in my area.
Should I continue raising my concerns to my new manager? At what point is it reasonable to go over her head to my old manager? What sort of things can I say to approach this diplomatically?