As Uno.Material is marked as a pre-release package, should the other Uno libraries' versions be upgraded to pre-release as well?
If you check the 'Dependencies' tab in the Uno.Material NuGet listing, you'll see that Uno.Material requires (at time of writing) Uno.UI 3.0.0-dev.1533 or higher (which is the version it happens to be built with). Therefore you should be fine using the Uno.UI 3.1.6 stable release or higher.