This type of behavior may very likely be related to the Android device’s power settings. For example, if a power optimizations or power saving mode is enabled on the device, there is a high chance the phone will put the app in a Standby/Doze mode. In the vast majority of all Android devices, this mode is triggered within just a few seconds once the screen is off and the device is at rest. Doze/Standby mode will cease all but the most critical functions, including network access, as indicated by Google.
However, the WebMonitor Android app will resume automatically once the Screen is unlocked or the phone is charging.
There is currently no supported way to safely programmatically get around this, but you may want to manually allow the Revcode WebMonitor Android app to run in the background from the battery settings on the phone.
For more technical details about Doze/Standby mode, please click here.