MudComboBox: Open/Close Icon is not being rendered.

[MathiasAndersson-TCXN]

Hi!
I seem to have a problem that i'm not able to recreate on your sandbox, which is a bit annoying.

The issue is that the arrow icons for opening/closing a combobox do not seem to render at all. Looking at the DOM that "adornment" does not exist either, its as if its failing to create it on render.

This happens with even the most basic MudComboBox, e.g:

<MudComboBox T="string">
    <MudComboBoxItem Value="@("Hello")" T="string">Hello</MudComboBoxItem>
</MudComboBox>

[mckaragoz]

Could you provide a screenshot?