Dying while playing Solo at higher difficulty than Master will softlock you in Kell's Fall. Instead of restarting the boss fights ("Your light has faded") you just respawn outside of the entrance to the fights on Mad Bomber and the final boss, meaning you cannot re-enter the fight. This results in a lot of wasted time. I get that it's not supposed to be solo content but it's still a bug. Ongoing issue since I unlocked GM level activities in August or early September.