As the message says, it's not a BUG but a tool that helps you to narrow down issues.
Here we have an infinite call to the post body within the post body.
Hence it can not work.
On the site you shared the login (username) is not valid anymore. Has it been deleted?
I deployed your Site's copy locally and on single products, turning on WP Debug an doing nothing else, I see:
( ! ) Notice: Trying to get property of non-object in .../plugins/unicorn-assistant/unicorn-assistant.php on line 116
I removed it.
I understand it is a DIVI Plugin, but it produces an error, that happens even if you fully disable Toolset, hence it's not related to a conflict and we need to have a clean page to test the issue.
I then commented the line in your theme's footer:
//echo do_shortcode('[et_pb_section global_module="35417"][/et_pb_section]');
And used render_view() instead, which is not solving anything, it makes it worse.
I solved this by using the suggested approach of assigning a Content Template to the single Post of Products.
Then it works.
Then also your custom ShortCode works.
So, the solution is also here, to use the suggested and documented approaches.
To solve the problem please head to Toolset > WooCommerce Views > Product Template File and choose "WooCommerce Views plugin default single product template"
Then create a Content Template to style your products and assign it to Products
After, check a single product to see the correctly rendered view in the footer.
As soon I re-enable "WooCommerce Plugin Default Templates" in the WooCommerce Views settings the issue will come back.
So, it should not be a BUG, since this is the recommended way, and what we integrate with, if you use DIVI and Toolset.
I even tested this on your duplicator re-enabling the error causing plugin mentioned above.