We have three test devices in our company that exhibit the same behavior, but the vast majority of our test devices do not show this problem. The apps in question always report that the ATT status is Denied. The apple settings are set to allow tracking globally just like you. Some are guessing that this could be caused by a parental control setup to block tracking or an enterprise remote configuration setup that is blocking tracking but we haven't been able to verify that case yet. We were able to simulate the parental control situation, but in that case, ATT status is restricted and not denied. Our testers, using those devices, have even tried doing a factory reset on the device and it still always started out with ATT denied.