In XMS 10.15 RP6, the device property "ASM_DEP_SHARED" is set to "true" even if the "Shared mode" setting of your DEP account is disabled.
New DEP enrollments in other 10.15 rolling patches are not impacted.
Workaround is to reset it to "false" in database -> "DEVICE" table -> "ASM_DEP_SHARED" column. An enhancement in future releases/rolling patches will be done to auto-reset this property.
Code bug introduced by DEP shard iPad feature in XMS 10.15 RP6.