Troubleshooting Loading Templates
Some shared or low-memory hosts have trouble loading templates. The page builder tries to identify this problem and fix itself.
However, if templates aren't loading for you, you should try lowering the template memory. This will break up the template retrieval into several chunks, putting less of a strain on low-memory hosts.
To do this, go to Site Settings > Templates > Template Memory, and select a specific memory setting like "Low":