Dealing with tack fuses
I assume you used a pre-programmed schedule. Now you know why so many people do not like these. Many setups are not considered by the people who do the programming of schedules for kilns. Tack fuses require longer and more careful annealing than full fuses. Slumping of tack fused items needs slower rates of advance. Draping of tack fused pieces require even more slow-ness. So it is not the kiln time. It is more likely inadquate annealing and subsequently too rapid a schedule with not enough annealing time and too quick an annealing cool.