Yes, sometimes my bags unseal. I think usually it's because they get damaged via transferring and flipping them --- the bag gets a little hole, or the seam weakens. Sometimes the cheese seems fine (no mold or anything) so I just let it go. Other times, I can see mold developing so I'll unpack the cheese and wipe it down and then reseal it in a fresh bag. Also, sometimes I'll double seal the bag if I feel like it needs a little extra security....