dont override Avalonia.X11 nuget version.
MODIFY
Directory.Build.targets
Directory.Build.targets
<ItemGroup>
<PackageReference Update="Avalonia" Version="$(AvaloniaVersion)" />
<PackageReference Update="Avalonia.Desktop" Version="$(AvaloniaVersion)" />
- <PackageReference Update="Avalonia.X11" Version="$(AvaloniaVersion)" />
<PackageReference Update="Avalonia.ReactiveUI" Version="$(AvaloniaVersion)" />
<PackageReference Update="Avalonia.Xaml.Behaviors" Version="$(AvaloniaBehaviorsVersion)" />
<PackageReference Update="Avalonia.Xaml.Interactions" Version="$(AvaloniaBehaviorsVersion)" />

dont override Avalonia.X11 nuget version.