Unable to Move or Substitute Players in Team Management (Some Teams Only)

Game: EA SPORTS FC 26
Platform: PS5
Game Mode(s): Kick-Off
Squads: Custom (many player transfers made manually)
When managing certain teams, players become locked in their starting positions. I cannot move them to the bench, reserves, or change their on-field positions in the Team Management screen. The game leaves them in default positions and ignores substitution or position changes. This happens consistently after loading the game.

However, this problem does not affect all teams — some teams still work normally

Working normally: Latium (Lazio), Chelsea, Werder Bremen
 Bugged / locked: Arsenal, Inter Miami,
After editing multiple teams (transferring players in/out, customizing squads), some clubs become uneditable in Team Management.
When attempting to:
Swap a starter with a bench player
Move a player to or from the reserves
Change a player’s position manually
…the game either does nothing or resets to default when I back out of the menu.
This persists even after saving the profile and restarting the game.
It appears tied to the team sheet itself — some clubs’ team sheets are now “frozen,” while others behave normally.
I made numerous manual player transfers before this issue began.
Importing or creating new team sheets does not always fix the problem.
It affects both default and custom tactics.
Other players on the forums report similar symptoms — possibly related to team sheet corruption or squad data issues.
It's horrible, that one of the most important features (CHANGING PLAYERS IN A SQUAD!!!) is so bugged. How can that be? Why isn't something like this fixed right away?