Page Builder hanging remotely

I have page builder on our site. It seems to work locally as i downloaded the site to start switching off plugins in case of conflict but it seems to work ok.

Its running on an nginx server, is there a known issue with that maybe? Page builder itself hangs when you click “edit” in a page block for example and then it just shows a white page with no content and a spinner.

Any ideas as we can update no content on the site now.