I am having same issue, unable to update my N3DS to 11.1. I downloaded 3DNUS and input the title ID, but it says there is no match. What can I do? How can I update my system? My N3DS has A9LH and Luma installed.
11.0.0-33U is the firmware you want, and 0004003000008F02 v25600 is the title id and version of the cia that you want. If you type in "11.0.0-33U" and hit enter, it'll grab all of the files. If you have "Pack as CIA" and then "New 3DS" it'll download what you need. Once completed go to the appropriate folder (by default it's a subfolder created where 3DNUS runs from. Example, mine is installed to C:\3DSNUS and the folder it creates after I did what I described above is C:\3DSNUS\11.0.0-33U. copy the cia over and then install it. To simply enter the titleID and download it, you need to have grabbed the correct list first. This way is easiest. You can cancel after it downloads. It'll download within the first 5 items I believe).