[Everyone in this account] was turned on without my knowledge.
One day, I created and provided an account for a cooperative company. Even though the account did not yet have any groups or dashboards shared, several dashboards were available for viewing.
When I checked the permissions of the dashboards in the CLI, the same settings were granted as when [Everyone in this account] was turned ON. (e.g. QueryDashboard to default namespace)
However, when we checked with the creator, he said that [Everyone in this account] was not turned on for the majority of the dashboards that were made available for browsing.
In fact, when I opened the [Share dashboard] of the dashboard, [Everyone in this account] was turned on, but it was immediately turned off by itself.
After that, I checked the permissions in the CLI again and found that the QueryDashboard and other settings in the default namespace had disappeared.
I have left a video if it is difficult to understand.
If anyone else has had a similar problem, or if any QuickSight administrators are seeing this, I would like to know how to deal with this phenomenon.