Adding Custom Class to Content HTML Box -??

Hello
Great Plugin

I notice that when I try to add a custom css class to a content HTML Box using:
Custom Class htm-cust-class

in layout

I get the following :

<div class="col-sm-1 ">
<span class="caldera-forms-conditional-field" id="conditional_fld_9506846_1">
Test HTML DATA</span>
</div>

Yet in the box on layout I have: Custom Class htm-cust-class

can’t seem to get the content box to accept a class like the others ??

Am I doing it wrong ??

cheers

https://www.ads-software.com/plugins/caldera-forms/