Hard to make any changes to the theme

I installed Upfront Builder + two upfront themes (Gillie + Spirit), and tried to adjust it to my needs. However, using my iPad, I am unable to resize, drag&drop, change text, or basically do anything besides removing pieces. I had subscribed to the tutorial, but I can't even get through part 1 of the course, because it's not working. So I also tried on my MacBookPro, but there I have almost the same issues. Different things do work, but other things don't, such as switching images and such.
Are these known issues?