I'm forced to play U-19 pre-season games

Forgot to add I'm playing Sevilla

Thank you for making us aware of this. Would you be able to share your save game in which this is happening so that our QA team can take a look into this further? A guide on how to do so is available here:

 
 

Done. Not sure if you'll be able to see anything in there though, I have "fixed" it by hiring a new U-19 manager and asking him to take all the responsibilities in the welcome message and I have saved a few times since then

 

File name is

Mariusz Pudzianowski - Sevilla.fm

Do you happen to have a save file from before you hired a new U-19 Manager?

There are several tabs you need to set the manager in order to him fully have charge of the any of the reserves teams.  The first is in the "Staff Responsibilities", the second is in the "Training Responsibilities", the third is in the "Tactics Responsibilities" and the last one is in the "Match Responsibilities".  If you have set in all of this tabs and still have problems, then your game is bugged... In mine, I don't have this problem.