Tell us what you are trying to do?
I have set a dynamic source paragraph a custom class with a smaller margin, because right now it too big. The same class is set for other blocks too and it works. And also the font size set doesn`t change.
Is there any documentation that you are following?
Pressing enter does nothing. I dont the problem is there, because the font size which is set through its menu doesn`t change either. In the inspect element screenshot you can see it adds the font size and class to a empty paragraph before the actual paragraph. I dont know why.
Can you please share problem URL and access details.
*** Please make a FULL BACKUP of your database and website.***
I would also eventually need to request temporary access (WP-Admin and FTP) to your site. Preferably to a test site where the problem has been replicated if possible in order to be of better help and check if some configurations might need to be changed.
I have set the next reply to private which means only you and I have access to it.