For Android tablets running Android version M and greater, they introduced "Battery Optimization" which will suspend apps and delay push notifications when the app is in the background or screen is locked. To make sure the Menufy app doesn't miss any new order notifications, you can disable this feature for only the Menufy app by following the guide below.
-> Open the Settings app on your device
-> Find Apps & notifications -> Advanced -> Special app access -> Battery optimization
-> Select "All Apps" from the dropdown
-> Find "Menufy Restaurant Console" in the list
-> Tap it and set to "Don't optimize".