Sorry just realised there was a typo in the first question. I was asking if you currently use an EMM (Enterprise Mobility Management) to help manage your devices?
And for management mode, whether your devices are owned by your company or are owned by the employees (ie. BYOD)?
Also, do you happen to know the make and model of the phone(s) or device(s) involved? While it's great that you mentioned that each device was on Android 10, each manufacturer has a slightly different process for checking the IMEI number. Usually there's something in the "Settings" app that can lead you to it.