As others mentioned here already there seems to be an issue with MainWP child plugin and Elementor.
I had issues on different websites in the past few days. For example: I added a section and filled it with a background color. In the Elementor backend editor everything looks fine. In the frontend (the website in the browser), however, the section appears (I see the additional space showing up) but it is empty, no background color.
Another example: I have a section with three modules (a blog grid, a text block, an image). I edit them individually, change the margin, the font size, the image size etc. In the backend everything looks good. In the frontend the layout edits do not appear (the image size was not changed, the font size was not changed, the font localization was not edited etc).
After I disabled MainWP Child plugin, all edits appear correctly in the frontend.
One detail: yesterday while working on a different website with the same issue I disabled LearnDash plugin which also solved the problem. On that specific page MainWP child plugin is still running. And so far, editing that website is possible also with MainWP child enabled.
MainWP Child plugin 4.0.7
Any suggestions how to solve that problem? Thanks!