When using Telerik.UI.for.Blazor 4.0.0 and 4.0.1 the avatar sizing styles get overwritten.
Example of what it looks like in my browser, despite trying to use the medium size
Below is the inspection of the styles. This shows the size style gets overridden by a default size styling that comes later in the css file.
below i've included a screenshot of the path of the css to confirm i'm using the Nuget included css file.
Also, a side note that isn't that important.
On the avatar demo page example you reference the Button constants instead of the Avatar constants.