Crossover for Work interview questions

I applied to four different positions (QA Manual Tester, Cloud Operations Engineer, L1 Customer Support Agent, Customer Success Manager), Despite passing the assessment stages, My applications were rejected for unknown reasons. The recent rejection I got was my application for the position of QA manual tester, which was the easiest of them all, where I scored a 100% in the Real work and still wasn't selected. It starts with Stage 1 (Basic Fit), then Stage 2 (CCAT) where you have 15 mins to solve 50 questions, Which I passed and was automatically moved to the next round, Stage 3 (Language), then Stage 4 (Skill Assessment) and Stage 5 (Real-Work). Passing and spending hours on the assessment stages isn't enough for impressing them and the hiring manager (IF THE POSITIONS ARE REAL). As my application was rejected and the reason given doesn't apply. I sent an email to support for a genuine reason for not being selected since I scored a 100% in the Real Work Stage. I didn't get a reply back.

I did all the assessments and made it to the interview stage. It was a basic interview though the interviewer seemed to have already made up his mind before we started. He seemed disinterested throughout. We finished and I got a fail almost two weeks later.