In some cases users are unable to uninstall Company Portal application on their Android devices after unenrolling or while troubleshooting enrollment issues.
There are 2 ways this can be resolved:
The easiest way for end user is by having the administrator “Selectively wipe” the the device, this will in most cases resolve the problem as long as the device has established contact with Microsoft Intune.
The other scenario is when the device failed before establishing connection with Microsoft Intune, the user will then have to manually remove Company Portal as a Device Administrator in order to uninstall the app.
Open Settings > Security > Device Administrator > Delete Company Portal from Device Administrators and reinstall the application.
The same instructions will resolve another problem you might encounter during enrollment: “Failed to activate Device Administrator”. This often occurs if a user had problems with the initial enrollment phase.