Avia Layout Builder not working

Hi there, we are trying to set up a demo import with the Gym layout, however when trying to edit the homepage, the page builder won’t load, instead the “loading” icon continues to spin continuously.

We have been through a number of posts from people with the same problem, and carried out the suggested steps, including:
– updating WP, Enfold and plugins
– deactivating all plugins
– clearing browser and computer cache several times

Please let us know the steps to fix this so we know how if it ever happens again. Login details are in Private Content.