Applied at new school district for Unknown

I recently went through an intense job application process with a new school district, and I thought everything was going perfectly. I had great interviews, and even received a verbal offer from the hiring principal, who congratulated me via email. HR informed me that I was the top candidate, and the only remaining step was to contact my references, including my current supervisor, which I hadn't informed about my job search. However, after they reached out to my references, the offer was suddenly revoked. HR told me they went with another candidate, but I managed to speak with the hiring principal to understand what happened. During our call, he revealed that my reference checks were not entirely positive, particularly from my supervisor. It seems there was a discrepancy between what my coworkers said about me and what my principal reported. He even mentioned asking her about areas I need to improve, which is a standard reference question, but I was caught off guard because all my evaluations have been proficient, and I recently received glowing letters of recommendation, including one from my principal. I’m feeling completely lost and frustrated, as it seems my principal’s feedback was the main reason I lost this opportunity.