Soo, I occasionaly play on my laptop, where I dont have the addon, and I collected some items. Later on I logged to my pc to find then unregistered in the addon (Showing as Not collected). Even if I wear them, they still dont show up as collected, I tried to put them in bank as well to "receive them again", but still they didn't check as collected.
It was my mistake that I didn't have the addon downloaded, but I had like 10% of the game downloaded there, so no addons >.>
Is there any way how to force-update items in my inventory? Some are soulbound, some are active in my transmog library, but.. still show as not collected :/

Shift Left Click the ATT Icon or Header to manually refresh.

If you close the game down by Alt+F4ing, that some times causes the game to not write saved variables.

Oh great, that solved it, thanks, a lifesaver! :D