Hi!
We have only a few Android devices in our organization (but lots of iOS/iPadOS devices) and most of the Android devices are for special purposes, which means that they really don't notice if they loose contact with the ZENworks server. We also kind of missed the Google FCM API changes, but I think I fixed it now. At least a few Android devices has refreshed since I reconfigured FCM.
However, I have a Samsung in a drawer for testing purposes, I haven't used it for a year or so but yesterday I got it out to test something. Of course it won't talk to ZENworks. Not only has the Google FCM API changed since I last used it, the MDM server certificate has also been reminted recently. The ZENworks app on the phone says "The Device Certificate is not valid. Please contact your administrator". The device policy that was applied to it is quite loced-down, it doesn't allow factory restore, removal or inactivation of ZENworks app or anything that could release the device from management. Is there any way to wipe the device or otherwise overrun the policy that still applies but cannot be managed from ZENworks now. I tried adding the new MDM server certificate in settings, but that didn't help. It is perfectly fine to wipe the device completely, by force if needed. If there is a way to do this it cuold be useful for re-registering other Android devices that has lost contact.
Kind regards
Bengt