Different restore code for Blizzard authenticator?

Sorry to ask a dumb question, I just tried to back up my authenticator restore code after realiazing I should have done so earlier. However I noticed that the “Restore Code”

  1. seen from phone Authenticator itself

  2. seen from web account portal in security tabs

are not the same, completely different. They share the same serial number though.

Is this normal? Thanks.