The “error message” is just an indication that some of the time and size limits on PHP are lower than they would like. But that shouldn’t automatically cause the theme to be stuck in loading. It could either cause the builder to crash if it exceeds the limit, or just work fine.
I may have the real cause for the loading issue. I found 8 issues while inspecting the page. The screenshot is attached below. the reason for not loading the theme is mainly caused by the mixed content (Some are loading from http and others are from https)
Anybody knows how to load all the content from https?