@shane, for info, this problem is resolved when the Avada Builder plugin is deactivated (which breaks the site).
I do not require any support from you, as I am at stage 1 of moving this site from Avada (this problem makes things messier!), but thought you should be aware.
You may wish to raise it with your dev team, as I'm sure there are plenty of other sites out there using Avada.
I did some testing just now to double-check how this works with Avada.
It is true that if you use Avada Layouts to create a custom template for some post type then you cannot use an edit form in the way described in the our documentation.
It is possible to use Toolset edit forms, but only if you do not use Avada Layouts to design the template for the post type. You can instead use a Toolset template for that post type, and continue to use Avada for the rest of the site.
