Why doesn't Backdoor work through APK firmware?

Question

Kali

Good evening! Help who can, the problem is, that there is a VDS server with Kali and TheFatRat, made Backdoor - works in the global network, made Backdoor in the APK file - does not work, and how many APK games, applications went over - either they are not patched, or run on the phone, but metasploit does not see them. Who can provide a verified APK for flashing or who can flash it themselves? Because it's rather strange that a pure Backdoor works, but a wired one through Backdoor-apk does not, I also tried it through TheFatRat old method, but the application just crashes. Thank you in advance!