Seed- code issue

When I registered a new device (model T) I chose Shamir -code for the test (5x20 words) When I want now to register the device, system wants seed-code. It gives me a choice of 12-33 digit codes. I tried one of the five sets of words from the Shamir-backup code, but it doesn’t work. :slight_smile: Will you please explain to me how to fix the mistake? Thank you.