Euro Cup Bug --- or is it??

If it is a genuine bug then perhaps a Mod can move as appropriate to bug section,, but not sure if I have just missed something or not.

Im in season 4,, and have registered my 25man squad. It did the usual,, 4 trained by club 8 in nation and said 20 and below no need to be registered. I have just came to the first match in the group stages and noticed that ALL my young players 20 and below that I didnt add to the register (as I shouldnt have to ),, are all marked as uneligible for the game???

I havent noticed this before,, and im not sure now if this is the first time I have started a euro cup since I updated to the latest patch,, but i know my youngsters could play before!!

Is this a bug ?? and if so,, is it a common one with even a fix ???

Anyone else had this problem ??

Maybe not a bug, FM has changed it this year the ruling is

They have had to played for the club for a certain amount of time between the age of 16 and 21

Apparently there's a note of this in the registration screen.

I believe its 2 years that the player needs to be on your team before they're eligible without registration, and if they do not need to be registered, there should be a U21 status on the squad registration screen next to their name.