Fix Wordpress Saving issue with BeTheme Muffin Builder

I have an Wordpress website running 5.1.2 and the BeTheme v15.4 by MuffinGroup. This isnt a website I have built but one we have been asked to manage and there seems to be a recent issue that has come about with the muffin page builder not allowing the page to save. The issue is that any page which uses the muffin builder cannot be saved in the wordpress admin. You can make changes to the page and click save but the page wont save and just shows "saving...." then times out with nothing being saved. If the page is a basic information page, not using the muffin page builder and you edit the page and save it, it works fine. The same with new pages, if you create a new basic page and save it that all works aslong as its not using the muffin builder. But if you use any part of the muffin builder to design the page it wont let you save it. This maybe a simple fix but i'm running out of time to fix. Im looking for a wordpress expert to diognose and fix this issue ASAP.