Issue with upgrade Xamarin to .Net 6

I decided to try to upgrade the old Xamarin Forms app to .Net 6 and found an issue.

Error: error XFVM001: Target Framework Version is currently v6.0 and must be greater than or equal to v9.0 in order to use Material on Android.

Also, the output contains next line:

warning XA4211: AndroidManifest.xml //uses-sdk/@android:targetSdkVersion '30' is less than $(TargetFrameworkVersion) ''. Using API-31 for ACW compilation.

The new project file looks like that:

<Project Sdk="Microsoft.NET.Sdk">
	<PropertyGroup>
		<OutputType>exe</OutputType>
		<TargetFramework>net6.0-android</TargetFramework>
		<TargetFrameworkVersion>v30.0</TargetFrameworkVersion>
	</PropertyGroup>
</Project>

I suppose it is somehow related to Xamarin.Forms.Visual.Material.  Any ideas what is wrong?

Update: I tried to use the upgrade tool, but it failed too. It was not able to find the nugets for some reason.

Update 2: Sample