Hi there
There's a problem with the way you are tallying the completion of the Family Familiar meta-achievement in Legion. In order to complete this you have to complete 10 other achievements - Aquatic Acquiescence, Best of the Beasts and so on. Each one of these achieves requires you to defeat any 12 of the 15 World Quest trainers with a team of the same family of pets - Critter, Beast, Elemental and so on. The problem you have is that, as soon as I beat 12 trainers, ATT seems to think that I have beaten ALL 15 and marks them as ALL done. One look at the Achievements panel shows there are still often remaining trainers to beat. It doesn't effect the achievement progress but as I was using ATT to track which trainers I had beaten with which family teams it is no longer accurate after I got the Family Familiar achieve. Is there any way of making this accurately track the trainer completion regardless of whether I've finished the achievement or not. Thanks

Unless there is any further reward from completing the tamers after you have gotten the reward, they will all be marked as complete which is consistent with how ATT operates in other scenarios.

I would argue this is not a bug and the general behavior of how ATT work

Technically this is how ATT has functioned for all Achievements, in that the Criteria of a Complete Achievement are inherently considered complete, since the only purpose of the Criteria is to obtain the Achievement. For the Achievements where only partial completion of Criteria is required, we get this type of situation.

Maybe in the future there will be less to do in the game and a bigger outcry for being able to complete individual Criterias of already-completed Achievements, but for now that isn't on the list of features to add.