Issues in terms of theme customization : testimonials and Promotion Headline

Hello, I am currently encountering 2 issues with the Clean Enterprise PRO theme in terms of customization. 1) I can’t add more testimonials to the first one (I have put 2 in the No of items box). Only testimonial 1 appears and it’s also impossible to add the client’s logo, which does not appear. 2) Then, regarding the Promotion Headline, the inserted image does not appear in the background either. P.S. I have the “Essential Content Types” plugin; I have reloaded the page each time and I have “published”, but nothing changes. Where does the problem come from and how to fix it? Thank you for your help ASAP.