Purple And Blue Bug(?)

Hello, I'm new to this forum and I'm not sure if that's the correct place to ask so if it's not, someone correct me please

I'm having trouble with Purple and Blue quest, the game doesn't detect me dropping the Ancient Soul on the sacrificial table. Tried right clicking it, but the item just disappears when i do so and nothing else happens. I've had to kill the Gryndilin Chief five times due to that. Nothing i try appears to work

Any help would be appreciated

 

1) Make sure you are doing the step correctly
2) Try /class for 20 seconds
3) Change world
4) relog
5) try 1.12.2

 

None of that works

 

Create a bug report then

 

Ok thanks