Validating Entities when connection string is using a Trusted Connection

I have a database connection setup using a 'Trusted Connection'.  ie:  (Server=myServerAddress;Database=myDataBase;Trusted_Connection=True;)

The IIS application pools are changed to run using a Windows domain account user.

This connection's 'test' button works fine from within Service Center. 

The application runs fine and can read/write to that database.

However, Service Studio and Lifetime cannot validate the entities during the '1-click publish' or compiling in LifeTime.   It errors with :

"Validation Warning
Couldn't validate that Entity 'myEntity' in extension 'myExtension' is correctly defined: It was not possible to connect to the database to validate the qualified table name '[myDatabase].[dbo].[myTable]'. Runtime errors may occur. Module : myEspace"

We're running v10.0.902 in Service Studio and 10.0.816.0 on the servers. 

I must be missing a config somewhere to set it to use the domain user account. Any ideas where?

More info:  When I'm in a Aggregate the 'test query' fails with this error:

We're sorry, but there was a problem obtaining preview data:

Database returned the following error:

Login failed for user 'MyDomain\MyOSServerName$'.

Does that user have access to SQL and have the right mapping to the database needed to be accessed?

Yes, the user account has access to SQL and has the right mapping to the database in the Database Connection configured in Service Center.  Its just in Service Studio and LifeTime that it can't access the database. Apparently I need a way to tell Service Studio to 'run as' this service user account. 

When you're configuring the Outsystems database, you've got 3 users: <user>log, <user>run and just <user>. As far as I know, the <user>run is being used to query the database from the front-end nodes. The user <user> is being used when you're querying from your service studio on your own machine (eg. test query).

To go back to the first question: I also get the warnings that the external entities cannot be checked during publication, but I never had any troubles with them. I always guessed it was by design, because I can imagine it'll slow the publication down.