Ionic 5 React Capacitor Appflow Build Issue installing apk on Android 6

I built an app using Ionic 5 and React.
Then I used Appflow for building APK.
All is well.

Problem is that APK cannot be installed on Android 6 version.
As per the browser compatibility docs on the official site, Android ver 5.5 and above are supported.

I am not using any cordova plugins. Only capacitor.

Am I missing something? Any help, tricks, suggestions?

Thank you in advance.