APK fails to install the second time

I generate APK by doing following in Android Studio: Build -> Build APK(s).

I copy this APK in Phone's memory and launch it. It installs fine, but only for the first time. I then uninstall existing app and launch the same APK again, now it says "App Not Installed".

If I copy the same APK from my computer to this phone again, then again it installs for the first time only.

Why my APK is not installing?

The Android app not installed error can be combated after resetting app permissions. Go to Settings > Apps > Reset App Preferences/Reset Application Permissions. After this, third-party software can be installed on your device.

Why my Samsung can't install APK?

Are trying to install or download the apk? Usually that happens because you have files left over from a previous version or download, or if the apk is incompatible with your phone, either the model or version of android and so the installation keeps failing.

Problem with Google play update, Open playstore -> Play protect and turning off Scanning device for security threats.