Android Version 6.0.1
and a NEXUS 9
This is to update you on the testing results. The device Nexus 6 with Android 7.1.1 was used, and in our case, no issues were registered.
After some more investigation and testing this is what has been found out:
Apps usually have some background in themselves and if the device used is not very productive or the app is too heavy for the device, this background tends to be displayed for some period of time before a splash screen or other content is loaded.
Generally, this behavior is impossible to change but the white background can be replaced by, for example, with the grey one.