This bug has been fixed in the patch.
If you get/have this bug on your map, do not save your map or the chests will be saved as empty and the original data will be lost.
Wait for the patch.
If you've already saved your map in 2.0, then I'm sorry it's too late, the data is lost. Unless you have an auto-save file that was created by 1.92, or a back up.