AIBU to think staff who work half days are not treated the same as full day staff?

[user9300922]

I work 4 half days a week and everyone else works a full day either full time or part time. All the full day staff all have set jobs and I don't.
I started having a job that I was doing on the days I was in but now another full day staff member has started and she has taken on that job.
I feel like I don't have a role like everyone else, its starting to knock my confidence.

None of us can tell if YABU or not as we don't know what the work is, or what the culture of your place of work is.
I've worked with people over the years who work mornings only, and, overwhelmingly they very much welcomed being treated slightly differently, as they wanted to do their hours and leave, due to other commitments, or living with illness or disability.
But I've worked with many, many PT colleagues who are not treated differently at all.