There is a bug with clear button in TelerikNumericTextBox. Steps to reproduce:

1. enter value
2. click on clear btn. to clear value
3. click outside input
4. click on input, at this point value appears again

code:

<TelerikNumericTextBox @bind-Value="@Price1" ShowClearButton=true/>
<p>Price: @Price1</p>
@code {
    private decimal? Price1 { get; set; }
}

Here is a short demo: