Pile of phantasmal residue can't be charged
Interacting with the skill point will not give you the dialogue to use the Pile of Phantasmal Residue if you have uncharged Quartz Crystal in your inventory. Charge the crystal first and/or remove uncharged ones, then use the Residue at the skill point.
It worked. Thank you. It’s still a bug nonetheless, a minor one though.
Yes, it is (or maybe oversight would be better). But it’s always good to know a work-around, rather than being stalled by it. =)