What are the version and build numbers of your MobiControl server?  If you can't have device license released after sucessfully unenrolling or deleting an enrolled device, I suggest you to open an official support case at https://www.soti.net/services/log-a-case/

The major difference betwen unenroll and delete is that the device icon still remains in the web-console after unenrollment.    Thus, after "unenroll" opeartion,  the associated device information from last communication before unenrollment, log entires, etc. are still easily accessible via the web-console.  If a device has been deleted, similar device/log information may only be read out directly from relevant tables in the MS-SQL database.

just find some info regarding the mode <0 ,   i think i have to reset the value,  will try tomorrow. 

Hi,

We have identified an issue in releasing App Store licenses when the application is no longer targeted to a specific device.  The fix is available on MobiControl 14.5.7 and 15.3.2 when it is released. 

this morning I tried to set the devinfo  -  mode value to -1 for some devices,   these licenses get regained.  

but after few mins,  i believe these devices still trying to connect the mobicontrol (already deleted from mobicontrol web consle) and the mode value reset to 0 again. 

Hi Purolator,

Thanks for posting in SOTI Central.

Please find the difference between Unenrollment and deletion of devices below:

Deleting a device removes it from SOTI MobiControl management and database. It is useful for devices that have been stolen or reached their end of life.

Unenrolling a device allows you refresh devices for new circumstances such as a device transfer or if you want to use another add devices rule

Unenrolling Device

Also, if this post has helped you in solving your inquiry, I would request you to mark the particular comment as "is solution", so others may benefit from this information.