FMRTE Player Attributes change over time despite using Is Frozen in Player Personal Details

I created a player in FM24 Pregame Editor.

Once I started the save, I changed ALL of his Attributes to 20 except Controversy, Injury Proneness & Dirtiness.

All went well for about 6-8 games. As you can see the number differences in both photos, MOST went from 20 down to 15 or 16.

Has this happened to anyone else? Am I doing something wrong?

I know I am clicking on the Freeze ball in the Players Personal Details section and then Saving the changes.