Toxic Krait Historian bug?
There are a few threads on this. A few people, myself included, got stuck at 23/24 but fixed it by revisiting ALL the obelisks on an alt and making very sure to have no aggro during the whole channel. For me it was the 24th one re-done that triggered the achieve, and someone else posted the same thing.
https://forum-en.gw2archive.eu/forum/livingworld/tower/23-24-obelisks/page/2#post3126407
Post with dev comments. Hope it helps.
“Whose Kitten is this?” – “It’s a Charr baby.”
“Whose Charr is this?”- “Ted’s.”
“Who’s Ted?”- “Ted’s dead, baby. Ted’s dead.”
“Whose Charr is this?”- “Ted’s.”
“Who’s Ted?”- “Ted’s dead, baby. Ted’s dead.”