The joint compound was not cured. How long did you wait before sanding the joints and painting?

You can try and run a dehumidifier and get it down to 35% for a week or so and then try and repaint. It will dry out even after being painted but takes a while. I would recommend a good fan on each wall or just point one at a wall, move it after 8 hours or so and just keeping repeating for a week.