Question - was it smelling normal before?

Separately - I think there's a thread somewhere on the board about it - some humidors don't use spanish cedar - they use aromatic cedar (the stuff you like your closet). Makes a big difference. Does the cedar look red?

That aside, the smell could be from the glue that holds the humi together. Just my thoughts.

What you might consider doing (and I don't necessarily recommend it) - is getting one of those air neutralizers that absorbs smell without putting any fragrance in there.

Welcome to the forum.