It should be fixed according to the patch/hotfix notes:

Quote Originally Posted by NOC_EU View Post
The following issues have been addressed:
  • An issue in the Whorleater (Hard) and the Whorleater (Extreme) where the Tidal Wave cannot be blocked if two or more players simultaneously use the Elemental Converter.
  • An issue with Grand Company supply missions where supply and provisioning missions will not reset even though the next mission allowance has passed.