Solvd Software Development Engineer In Test SDET interview questions

NOT PROFESSIONAL ON BACKGROUND CHECK! I passed the interview, and we agreed on the pay rate and start the day. I signed the offer letter, and gave them all information required for the background check. They asked me about the education I have, and do have a diploma I was willing to provide, but they refused and withdraw my offer referring that this is not the process they want to proceed with. So disappointed. I would imagine if I'll give a 2 weeks notice to my current employer and then get announced about their change of mind. Not professional.