Applied at healthcare job for Unknown

I recently applied for an internal position at my healthcare job, where I've been working in the patient support department for four years. I’ve been on 12-hour shifts, which don’t fit well with my school schedule, and I was hoping to switch to an 8-hour shift at a nearby acute care hospital under the same network. My supervisor and manager both verbally supported my transfer, but I received an automated rejection email just 9 hours after applying. I know that the position is still open and hasn’t been filled, so I suspect my application might have been flagged by an automated system. I’m feeling frustrated because I don’t think my resume even reached the hiring manager. I’m looking for advice on how to navigate this situation and possibly get my application reconsidered.