Tunneling

[Brimy]

Do you find the tunneling with a particular kind of wrapper?
If your rH has been stable then I don't think your media is the issue.
The question is why is the wrapper & outer leaves staying so wet that they won't burn?

[Nature]

Do you find the tunneling with a particular kind of wrapper?
If your rH has been stable then I don't think your media is the issue.
The question is why is the wrapper & outer leaves staying so wet that they won't burn?

I don’t think the wrapper is necessarily wet, just less dry than the interior.

[Brimy]

I don’t think the wrapper is necessarily wet, just less dry than the interior.

Absolutely!
But it's wet enough not to want to burn. The question is why?
Maybe you should try dry boxing one and see what happens.