Managed to repro this 100% consistently.
If you have an Augmented Elekk on the board and then play the new Finley (Sea Guide), and then cast Ignite- the Elekk doesn’t just shuffle one extra copy of ignite into your deck. It also copies the whole hand that you earlier swapped with Finley.
Note: It does NOT shuffle in a copy of your hand if you only play Elekk + Finley, you have to play something like Ignite AFTER playing the Finley.