Ahrefs Shows DR 44, Semrush Shows DA 0: Why the Huge Discrepancy?

I noticed that my app is listed on one webside. I checked its Domain Rating (DR) in Ahrefs, and it shows 44, which seemed fine to me. However, I checked the Domain Authority on Semrush, and it shows 0. This seems strange. How could this be possible? I'm concerned about this discrepancy and would like to know how to remove my app from this webside.