Not working with s2member pro

I am using divi 3 comet cache free version and s2member pro version. I am not sure if this is a settings issue but when I veiw the page source I receive the message

Comet Cache is NOT caching this page, because the s2Member plugin set the constant COMET_CACHE_ALLOWED to a boolean-ish FALSE value at runtime. The s2Member plugin is serving content that must remain dynamic on this particular page, and therefore this page was intentionally not cached for a very good reason.

The message displays even when I am on a page which is not an s2member page.

Thanks Paul M

That suggests to me that the root cause of this problem is something to do with Divi. See Divi by Elegant Themes and Comet Cache