Why is the ‘row level security’ grayed out? Will the RLS work?

I have a RLS requirement, where I need:

• The user accessing the report to see only her/his own data.
• Teamleads can read their own data + their teams.

In the USER role, I have the RLS:

Users table  =[NT Username] = USERNAME()

In the Team Leads role, I have the RLS:

Users table = [TeamLeadUserId] IN SELECTCOLUMNS(FILTER('Users' ,  'Users'[NT UserName] = USERNAME() )

                           ,"Id"

                           ,[User Number])

In my model I have 2 facts, a classic one, and an AggregatedFact.

In my model I have the classic: “1 to MANY” User dimension to Fact.

Then I have a “Many To Many” User dimension to AgProfitCenter dimension

Why is the ‘row level security’ grayed out? Will the RLS filter the AgProfitCenter table?

Lastly, I don’t understand why if in the details it is clearly marked as *:*  in the Manage page it appears as *:1

Note:  dimension AgProfitCenter connects to AggregatedFact; which holds aggregated data.