job application

I recently applied for three different positions at Tesco within my available hours, and I applied as soon as the applications were announced. However, I’ve been rejected from all of them, not even a minute after submitting my application. I’ve worked for Tesco before in a different area, and I have other relevant work experience, so I’m unsure why I’m facing these rejections. Has anyone experienced something similar or have any advice on what might be going wrong with my applications? Any tips on how to improve my chances would be really appreciated!