Yes

Can't give you an answer for your specific resolution, but my resolution is relatively high and a UWHD format (3440x1440) and in the game there are no problems at all. Only the images during the loading screen are not made for UWHD, you then have black bars on the left and right but that is only during loading for a few seconds and in the game itself I have no problems at all and the full screen is used.

as far as I can see a physical version of the game

Oh no, that's very annoying 😥 Is there a possibility that the game was accidentally marked as "hidden" / "hide"? In that case, there is a "Hide" section at the very bottom of the "Games" tab where you can see the hidden games and remove that again. Otherwise this seems to be a technical error on the part of Ubisoft: https://www.ubisoft.com/de-de/help I hope you'll be able to access your Anno again soon. 👍

Has the seller ever played the game or installed it on his computer? As far as I know the Ubisoft games are tied to the respective accounts has the same problem with Anno 2070 had the game played on another account when I then had my own account I could not play it because the game code was already used. So it was installed on the other account. Therefore, I would advise you to buy the game again or via the launcher itself.

The code is on a folded paper inside the DVD box. It consists of 4 times 4 characters.

Yes, it's in there. You can then simply register it with Uplay and download it.

It was sent about 2 months ago. By mail

According to our information, this is a box with CD.

We will certainly try to offer it. As soon as our suppliers have more detailed information on this, we can probably include it.

Correct, this is the special edition with soundtrack CD and the lithographs :)

Provided we receive the games from our supplier in time, we will send them out so that they are in the letterbox on 26.2. :-)