Superstar career mode error message

Whenever I try to edit my avatar on superstar mode or add boosts etc, I get an error message appear on the screen and won’t allow me to customise my player, sometimes a completely random character will appear in games and during cutscenes.  
The message literally just says error and won’t allow me to proceed to the customisation page.

I've tried rebooting my ps5, clearing the cache & rebuilding the system, I’m using the most up to date version of the game and use a wired WiFi connection.
I’m so frustrated, don’t want to delete my current player as I’m halfway through a season 

Does anyone have any advice or experiencing the same?