With my project upon running UI Tests I get POST Failed error. I can't figure what is the cause of the problem. UITests Post Failed in Xamarin.forms, related to the same issue did not help.
On an actual device I get Instrumentation backend app installed (it runs as a server for UI Tests). But I am still getting POST Failed error.
How to fix this issue?
The problem is related to the Android OS version.
Instrumentation backend application does not work properly on new android os-es.
I created a simulator with older Android OS (Android 6.0 Marshmallow).
And ran UITests with this simulator selected in Visual Studio.
And all things worked.
Hope it will help someone who struggles with the same issue.
Old school things are better than new ones.