I noticed this a while back and let ZOS know, but it involved selecting Guild chat etc, but was fixed (although it took them a month or so) and I did know the magnitude of the problem until yesterday as it involves around Achievements as well as Master Writs etc. I'll lead off with a couple of examples which indicate some of the results of the problem, although there are many more.

The 1st one involves the Player Fs Armor and the Undauntes "This is the one achievement" where you buy about 20 people drinks etc. The 3 pictures below will show the following.
1. Looking at Brulo Bloodletter (who's the last person need to buy a drink for to get the large amount of Undaunted Experience.
2. Than trying to take to Brulo, and being told you have already bought him a drink, so you cant finish the achievement.
3. And finally a log of the achievement showing that it has not been completed.

https://i.imgur.com/4sZfpXD.png
https://i.imgur.com/4sZfpXD.png
https://i.imgur.com/1fvpM9H.png

The 2nd one involves the Player Fs Weapons who's in the process of collecting skyshards in Glenumbra, in the delf to find Search among the Shrieks shard.
1. The 1st Picture Shows the Log and you can see that the player needs to collect the Among the Shrieks shard.
2. The 2nd Picture shows the player looking at the skyshard and it's already been taken by him, so he's unable to collect it and get the required skill point or complete the Achievement

https://i.imgur.com/bXM43gO.png
https://i.imgur.com/o1dzpV7.png

If for what ever reason the pictures do not resolve i'll post them as a direct link from Dropbox in a second post

But in addition to these problems of Understating the Xbox Players Achievements etc (Right now i'm only positive that it affects XB1 players, but have a few friends doing it on PlayStation as well as PS), it's also resulting is a MUCH MUCH MUCH lower drop rate for Master Writs in terms of vouchers. A fully setup master crafter for Blacksmith, Clothing and Woodworking, will get less that 50 (50 is the high end of the range for) even though his crafting is at withing a few hunder of the max 17000 Achievement, and has less the 20 Motifs left to collect in the entire game including the 45 or so recently added.

And yes ZOS there's at least two of us that know how you created the problem.

Hopefully all of the pictures will post properly, but if now i'll do a second post from dropbox with the links so that you and ZOS can see the results for yourself.

thanks for listing