Forms and Form FIelds are not having classes added if the default "CSS Class" field is empty (Contao 5.3)

[bright-cloud-studio]

I believe this is a bug, I was fighting it a bit today and was able to recreate it.

I have set up a class for forms and form fields, "size50, size100, etc..". When you check off to apply this to a form or a form field, it does not get added to the HTML. Now, if you enter in any value to the "CSS Class" field that is standard with Contao, it will then add the selected styles to the HTML.

I suspect whatever is being triggered to add the classes isn't being reached with a blank "CSS Class" field.

[denniserdmann]

I can't reproduce your problem. Here is what i did:

1. created a new Toolbox Group
2. added a child assigned to forms or forms and specific input (see screenshot 1)
3. create form, create input text and add class
4. check frontend (see screenshot 2)

Did you install any other extension or changed the templates?