Apple Business Manager - what am I not understanding about the process?
Is the device enrolled with Apple DEP? If not, you can’t remotely remove activation lock with a simple click.

The WIPE button can do 1 of 2 things. It really depends on how it’s configured 


Wipe Managed App Data (these are apps from your Volume Purchase Agreement). The customer data stays in tact (including their Apple ID).
Wipe all data. This is probably the default configuration for your MDM. It erases all data as if the customer tapped SETTINGS -> GENERAL -> RESET


If you are NOT enrolled in Apple’s DEP then you’ll need to supervise the device. This will provide you with a lot more options. You can remove the Apple ID, change the background wall paper, turn on or off the GPS, etc.

Reference: https://support.apple.com/en-us/HT202804

I am an AirWatch MDM Administrator