Something's missing alright
The release/buyout/transfer fee is not a simple process in Spain in general, and again, simply paying said fee does not constitute a sale - the clause is actually linked to the player themselves in contracts and Athletic hold their players accountable in this manner, sometimes also demanding the VAT on top of the fee. Javi Martinez' transfer to Bayern is a prime example and ask KHR what he thought of dealing with Bilbao - they had to pretty much sneak the player out of the city at night, a bizarre transfer in the end
The good is that Pep has dealt with Bilbao as has Txiki and Laporte's agents are all friends with the City principals but perhaps more reason why Athletic will refuse to be handled too. It'll be complicated if he is indeed the target again