Skill book bug

Hello, I am level 88 currently doing Tier 7+ corrupted nexus quest and decided to use a yellow T15 waystone I looted during a group play, used it on a regular boss map node and cleared it, the dragon boss dropped a skill book and I used it but did not get any points to use

Now Doryani is selling T14 waystones, quest is still clear T7+ corrupted nexus

Please advise on what to do, thank you

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