What is happening:
Four quests can't progress are not working properly. To advance two of them I must talk to Graphite("Here he goes again" and "In my own little world"), but he just doesn't respond to "t" or rmb->talk at all. Third one("Metamorphic ventures") requires me to talk to Luster. That one talks, but only one phrase without an option to say something. Forth one("Rehearsal Roundup") I can finish but there is still one optional interaction with npc left(the last one) with Paper Trail. He, unfortunately acts just like Luster - by giving generic response without options. Since all of them are involved in Rehearsal Roundup quest, I suspect, it might be the cause.
What should be happening:
Talking interactions should work properly, I guess. I should be able to give music sheets to Paper Trail, talk to Graphite, persuade Luster that the stone is not a changeling.
Steps to reproduce the issue:
Honestly, I have no idea. I was dashing around Krystal Kingdom picking up all the quests I could and at some point fund myself stuck with this quests.
Screenshots of my journal: