Website down – 504 Gateway Error

Hi
My website crashed yesterday at 7 am, it’s displaying a 504 error and I can not access it or the admin panel.
after bouncing between Siteground and Sucuri to find the problem, a tech at Siteground looked into it and this is what he said:
“The problem that you reported is caused by the enfold theme that you have installed on your website. To elaborate, to try resolving the problem I first generated a backup of your website’s database and then changed the active theme to twentytwenty. As soon as I did this the website’s home page and admin dashboard started loading properly.

Afterwards I imported the database backup that I had previously generated so that everything is just as before.
With that being said, I’d recommend contacting the developers of the enfold theme or your web developer for assistance with this problem. We specialize in server management, security, and performance so we can not assist you with all website-related requests or problems.”

Would it be possible for you to look at my site and see if there is anything you can do to help get it back online? it had run fine with no issues up to this event.