It looks like the UI regressed somewhere as the DataGrid now shows sorting adorners on all RadzenGridColumns regardless of AllowSorting value (which default is false). My app suddenly was showing them and even me setting AllowSorting=false, it is still showing them. My current production app does not show them.
It looks like 1.0.8+ may have regressed this behavior. My currently deployed app without them is using 1.0.8
The issue was caused because of Font Awesome CSS (you've added it because of GitHub logo probably) and a bug in our DataGrid header cells rendering. Fixed immediately and the NuGet will be uploaded shortly! Due to better support of @bind-Value we've made a change in our Form components - added typeparam. Please let me know if you have any problems to update to our latest version.