This issue can be reproduced using the following code:
Razor<EditForm Model="@to" Context="EditFormContext">
<DxFormLayout>
<DxFormLayoutItem Context="FLIContext">
<Template>
<DxComboBox Data="@Strings"
ListRenderMode="@ListRenderMode.Virtual"
@bind-SelectedItem="@to.TestStr">
</DxComboBox>
</Template>
</DxFormLayoutItem>
</DxFormLayout>
</EditForm>
@code {
public class TestObject
{
public string TestStr { get; set; }
}
private TestObject to = new TestObject();
List<string> Strings = new List<string>();
protected override void OnInitialized() {
for (int i = 0; i < 1000; i++)
Strings.Add($"Option #{i}");
}
}