Has anyone here ever had this happen?

Some years back I bought a large container of Italian seasoning at Costco.
It had a very musty smell to it and the taste was so terrible that I had to
dispose of it. We could not eat anything made with it because it tasted bad.
I did notice that it said "Northern Italian" on the label. I had not noticed
this when I bought it. I perhaps wrongly assumed this was the problem.

More recently I had the same experience with some oregano. I now buy only
those labeled as "Greek" or "Mexican". No more problems. Until...

I opened a new container of thyme. It smelled musty. I couldn't really
remember what thyme was supposed to smell like. I was making soup. I put in
only a pinch but it seemed to give the soup an off flavor. I added more
herbs and that seemed to help somewhat.

Bought a different brand of thyme and there is clearly a difference to the
aroma.

In no case did the herbs look moldy. But... Could they have gotten moldy and
then dried? Not sure what the problem was.