Styling form in WebBlock popup

Styling form in WebBlock popup

  
Hey folks, 

I have an app (for creating tutorials and adding steps) that contains two modules - one module contains the data model and webblocks for the CRUD, while an other app implements these web blocks in web screens. One of those web blocks has a popup for adding a step.
However, if I try styling the input - both with a class and with ext. properties - the style doesn't show up. I also have a label that says that users don't need to add a number to the StepTitle - it's added in the TutorialShow preparation. This label doesn't show up either. All my dependencies are up-to-date and I can't seem to figure out what the issue is. I have added some screenshots to make it more clear.

Kind regards,
Robrecht
I can't add two attachments so here is the screenshot of my popup in Chrome. 
My popup still had the regular StepDetail webscreen as destination, not the StepDetail WebBlock.