QuickSight Security & permissions Problem

Hi,

I'm having an issue with QuickSight, when trying to grant access to other services, and click on manage:

I get this message "Something went wrong For more information see Set IAM policy" :

I don't understand why I'm getting this, when I compare the permissions of the default QuickSight role with the one that I have a second account, both are the same.

Many thanks in advance