Cloud Attach - Enrollment Pilot Group

Hi

We use ECM 2211

We gone through the wizard from Administration / cloud attach / configure cloud attach with standard settings. After finish wizard we go to "Enablement" Tab and change the "automatic enrollmentin Intune" to "pilot". Also we add a collection which contain only 2 computer.

Now over night all of our windows devices show up  in Intune not just the 2 of the pilot collection.

Now it is a bit risky to make changes and settings in Intune without a "pilot" group.

Did we make a mistake ? What was going wrong ? Is there a way to correct it, maybee delete all the wrong windows devices in Intune ? 

We are still at the beginning to use Intune so many open Questions at the moment.