Posting this in the hopes of finding more people suffering with the same problem that is that once you have collected the other 4 manuscripts from the dungeon, the final manuscript for Windborne Velocidrake will not drop.
I am aware that the manuscript is dropping as I have seen it it drop for others but after running this dungeon over 100 times now and seeing the 1st 4 drop for me in <20 runs there is clearly an issue affecting some players but not others beyond the realms of simple RNG.
It is not the 1st instance of this happening with the black hair manuscript for the cliffside drake and molten lava pack toy as 2 examples I am aware of, both of which to my knowledge have been fixed.
I’m having the exact same issue. I have collected the other 4 but this one will just not drop.
I’ve filed a ticket with blizz but they say there is no bug that they are aware of at the moment.
Ive seen plenty of other people having this problem (its the only one I really want so I looked into it!).
Really hoping I get it before the others Im missing!
I have this issue also. Asked support - they say just low chance, keep farming. Also created a bug report. Encourage everyone to create bug report as well, cause the more reports, the more chance the bug will be triaged and fixed.