Hi Jeeves
I have the same problem on my end too.
Had 3 unsigned players yesterday at end of season.
Today morning...they were added to my team.
When trying to train them...game would restart.
On checking contract...it said Player will return in X seasons.
I had the option to renew their contract and did so.
Now I have over 28 players in my squad and any new player I sign goes directly into my squad instead of remaining unsigned.
Guess I have an unlimited squad size now