adding second nationality in relations tab doesnt work. in player's info you can see his second nationality but when you select him in squad he is still considered as foreigner.

 

 

also take a read here some leagues the rules are hardcoded

 

 

as from what you show your post is misleading slightly .....in that you have been able to add a second nationality ?? if so that is working corretly

 

 the hardcoded league rules that is causing the issue I believe and this is proving impossible to bypass(I have tried removing these rules pre game but they are hardcoded for some leagues, the only way is in the players info pre game is to select he be treated as non foreign in Italy, cant see that helping you though. There have been complaints made to SI re this perhaps you need to complain too)