Complete White Screen and then Open the app

#### Describe the bug
Every time I open the app the screen turn to white for a while then the app will open! Why is that happened? Before that ain't happening even though I was get an update. And while the screen is white I can take a screenshot even though I turn on the screenshots prevention

#### Expected behavior
The screen should be turning to completely white

#### Screenshots

#### Smartphone (please complete the following information):
- OS: Android 10]

#### Additional context
- F-droid Version 1.1.7

I'm kinda concern if my app was compromise or It's just a bug. Please guys response on this one or add more security on the app like in Brair where when there's an app over draw the Brair app the brair stop working until those app that overdraw was turn off