W3 Total Cache Problem

I have an issue where cache code is being displayed on some pages in the footer. This started by displaying only when I was logged in. Now it is showing all the time. But it isn’t consistently showing on all pages. It is not clear to me what determines whether it shows or not.

I believe it is W3 Total Cache because the very long string of code starts with “1 | get | from in-call cache | ” and ends with ” AS total FROM wp_comments GROUP BY comment_approved Served from: ouestsolutions.com @ 2017-02-03 13:41:16 by W3 Total Cache –>”

Any clues?

Thanks!