Sorry for my English if there is any mistake 
Some time ago, did some DSiWareHax for softmodding a 3DS XL. Before that, I 'unlink' my NNID from my 3DS by modifying data from CTRNAND ('Removing a NNID without formatting your device' https://3ds.guide/troubleshooting), so I thought there was no NNID linked...
I did the System Transfer: neither NNID on my 3ds, nor in the 3ds xl. Now, I want to link my NNID on my 3ds but it says it is linked in other system.
Today I called Nintendo Client Support and they say that NNID is linked to a 3ds xl, although there is other NNID in that 3ds xl...
What can I do?
Some time ago, did some DSiWareHax for softmodding a 3DS XL. Before that, I 'unlink' my NNID from my 3DS by modifying data from CTRNAND ('Removing a NNID without formatting your device' https://3ds.guide/troubleshooting), so I thought there was no NNID linked...
I did the System Transfer: neither NNID on my 3ds, nor in the 3ds xl. Now, I want to link my NNID on my 3ds but it says it is linked in other system.
Today I called Nintendo Client Support and they say that NNID is linked to a 3ds xl, although there is other NNID in that 3ds xl...
What can I do?






