End of last year, we did some repair in the bathroom, so we moved out of that bedroom (the master bedroom). Everything was out. After the repair, we thought about move back. But we found that there is a strong musty smell in that bedroom after window/door closed a whole night.

This situation lasted for half a year, and I cannot figure out what's wrong. There is nothing inside the room now, nothing. No furniture, no bed. Nothing. hardwood floor, no plumbing in the walls. crawlspace is dry all the time. The only thing I suspect is that there are some hairline crack in the exterior stucco. I had some contractors came to take a look, they said it is OK, as there is water barrier inside.

I ever had a drywall contractor come and ask him to replace all the drywall. He said he didn't find anything wrong and replacing the drywall is a waste of money...

This is really driving me crazy. We have been out of the master bedroom for more than 6 months, and cannot move back. Any suggestion?