Title, tried it on many different swords, experience gain seems to be equal when not using it. Tried it with looting, still the same. Consumes drops, no extra xp. Ancient Knowledge effect works normally but not Knowledge of the Ages enchant.

Yes, i am having the same problem. I just updated to 4.0.9 since then i have same isssu ...

Sooo fainally, after updating to 4.14 my problem was solved. experience ratio is fine, i get my 100 of lvls in no time as it should be.

yes it was a issue with the way clumps handled dropped xp, should be fixed for at least pack version 0.4.12+