[Paul M]

Then there is no reason for it not to show.

The usual reason I have found in these cases is a broken plugin attached to the cache_templates hook, preventing the code from running. Without access to your boards plugins there is nothing else I can tell you. If you know what you are doing, then disable all other plugins on that hook (try the same for the other hook used - this is much less likely though, as it would probably show a visible error).