This exact situation is occurring on Ubuntu Studio 20230910. I cannot narrow it down as to why, but this removes the Qt interface as the common factor (Ubuntu Studio uses the GTK interface for Ubiqiuty). If there was a change to partman that happened to cause this, I'm not sure, but we might need to narrow this down. Further testing will occur using Ubuntu Desktop Legacy.
This exact situation is occurring on Ubuntu Studio 20230910. I cannot narrow it down as to why, but this removes the Qt interface as the common factor (Ubuntu Studio uses the GTK interface for Ubiqiuty). If there was a change to partman that happened to cause this, I'm not sure, but we might need to narrow this down. Further testing will occur using Ubuntu Desktop Legacy.