Demo-content can not be changed / unable to change new content

Hi there, I am using Enfold with the demo-content “construction” but sadly I am not able to overwrite the demo and save the new data. Every time I change text or photos on the portfolio- or page-level, everything goes back to demo after saving. All the new work is gone. Some parts I was able to change, but not “Services” and “featured work”. Every solution or hint is appreciated!

Best,
B.