German Under-23s

Has anyone else found when managing in Germany (I'm in the 3rd Div) that the only way to get around not having 4 under-23s in your squad is to not pick a full substitutes bench?

For example, I have a starting 11 picked, plus 7 subs, but only 3 are German under-23 players in the squad, so I get the expected message telling me so. However, when I ask my assisstant to pick the squad instead he simply removes a player from the bench so that I have 6 subs, and the game lets me continue. Is this a bug?

I thought the rule was for 4 Germany under-23 players in the squad, but the game seems to act as though a certain percentage of your squad must be under-23s.

Of course, I could be missing something totally obvious..

no this is the ingame way of solving the issue of not having enough players to meet a requirement. the same happens with a european squad for example if you can put in enough homegrown players. if you leave spaces it considers the spaces to be homegrown.