White Screen for Webviewer after POST redirect for Android

Hello dearest community,

I am facing a major issue on my Android app. For iOS it is working fine. I access a web app through webviewer and log in. The login follows a saml algorythm and posts my userdata to a callback url and loads the webpage behind that callback url. All I get for Android after entering my login credentials is a white screen.

Is there anyone who has an idea on this?