As the game goes,FMSE cannot find the players when they age become older.Such as Cristiano Ronaldo,I can search him and find him when he is 37 years old. But I cannot find him when he is 40 years old.This problem has lasted two years in FMSE19 and FMSE20.
That is because these players change type from player to player/staff and FMSE can't read this type.
I've been asking Thanos for a while to add it, but no luck so far. Hopefully it can happen in a future update of FMSE21.