My App is running fine for all the android version but I have noticed that in Android 8.1.0 (Oreo) when I go the screen from portrait activity to landscape activity and when I press back button it shows the abnormal behavior.
Screen auto rotate from landscape and returns it to normal. It looks like Activity is restarting itself.
Below are the activities which is define in the manifest file.
<activity
android:name=".Home.TrainingsActivity"
android:configChanges="keyboardHidden|orientation|screenSize|layoutDirection|locale"
android:screenOrientation="portrait" />
<activity
android:name=".Home.ProgrammeActivity"
android:configChanges="keyboardHidden|orientation|screenSize|layoutDirection|locale"
android:screenOrientation="landscape" />
We also faced the same issue with Oreo. We actually can't triggered why its happening with the specific OS version. But we do had a solution to cater this problem. You can add force Orientation to portrait when finishing your landscape activity. add this this with onBackPressed() methond in ProgrammeActivity.
this should solve this abnormal behavior :)