Interesante:

No doubt that there exists a different (original) version. Kygo himself has said (via the interview with his manager in VG):

Bøe synes låten ved første ørekast hadde likhetstrekk med den nå 25 år gamle U2-hiten «Even Better Than The Real Thing».

Which means: "First time Bøe heard the song, he thought it had some similarities with the now 25 year old U2 hit «Even Better Than The Real Thing»".

So he was asked to remix it, not to write a song with U2. It was already written (and recorded) when he came in.

SalU2, Nelson.