I have periodically had it happen that Fargoth "stands me up"
I suspect it could be some kind of bug that occasionally occurs.
As Mr.Sir mentions though, don't worry about it. In terms of usefullness that ring does not have a particularly long lifespan. Your character will soon have enough hit points that the paltry few that can be healed by the ring won't matter, and you will quickly discover items with much better healing capabilities, not to mention healing spells if you develop some skill in Restoration.