With the latest patch all of my completed quests seem to have disappeared from the main and sub lists. I've lost a lot points.

I can confirm that since the new 8.2.5 patch, something is going on with quests. On a low-level alt, I've been choosing zones to quest in that provide missing appearances. Since the patch, the quests which provided new transmog (or at least a new source for that transmog) no longer show up in the lists. I'm running in completionist mode.

In debug mode, I can see that I am missing transmog "Starwhisper Monnions" for my druid. It is collected but not from this item.

In completionist mode, however, I do not see this item.

I'm happy to share any more information it you need more to debug the problem.

When patch 8.2.5 hit, blizzard changed up some events that fire at login and it caused some really strange behavior in unexpected areas. This was addressed in release 1.9.9b. Can you verify if this is still happening to you?