Android auto-updates manually installed apk, how to disable?

Question

Android

Hello everyone, such a problem: auto-update is disabled in the market settings, and everything is fine with that, no applications are updated automatically, however, manually installed from apk, after a while they quietly update to the latest version.
For example, there is a backup of the old version of MX Player, made through ES Explorer, in this version there are no problems with DTS sound on my device, I install it from apk, it costs for a while, and then once, and the next time I start the player is already the latest version ...
In the software itself, an update proposal pops up, when you first start the old version, I click "do not show again", and that's it, it stays for several days, and then it is updated.
Android 6.0.

Answer 1

Most likely this auto-update is loaded in the application itself.