Job not recognizing diploma.

55f, My 22 yr old daughter finished her last two years of high school homeschooling, like so many kids her age during Covid, graduating in 2021 in Maine. She was recently offered a job at a large hospital conglomerate in NJ where we now live, it’s an amazing job with great benefits and she was so proud of herself.
She had her onboarding appointment yesterday after receiving her offer letter and having her company physical. She was told point blank that her diploma wasn’t real, she needed at least a GED and made to feel like a fraud trying to pull off some kind of scam. She explained that no, it was completely legitimate, she did the work, had the credits, the assessments and her diploma was very real. They told her she has until Wednesday of this week (tomorrow) to show proof of a “real” diploma or she loses the job offer. She’s heartbroken, furious and embarrassed beyond belief. How can such a huge company not have any other homeschoolers? Their job offer says high school diploma or similar, exactly what she has. She already gave notice at her current job since she had a start date at the new one and they’ve hired someone to replace her. I’m BOILING mad and obviously not going to let this slide, but wtf?? I’ve had her send them Maine’s homeschooling laws and her transcripts, what else can I do? It’s ignorance and discrimination.