App is not updating

Hi Antonio, 

Have you done any local device debugging? Pulling a bug report and running through for instances of packagemanager or your com.package.name should indicate if the device is at least trying to install the application. 

Since you use windowed also there will be references to schedules through Google Play services, and you can then whittle your search just to between these windows.

Has the app changed in permission requirements, distribution requirements, or anything else in recent months? I often see apps stop updating when the dev adds in a new permission for a component that a device doesn't support, so if your devices miss camera, nfc, or other optional components the app is mandating, this will also prevent updates. 

Finally, you can set minimum version code in-policy for the app in question on a subset of devices to force it to stop what it's doing and install the latest version immediately. That should show you visually what the issue may be. 

You may also consider taking a device out of kiosk policy and push into another, with windowed still set, and see if this makes a difference over a day or two.