From RMS, check if you have monitoring enabled and that you have enough credits. To do so, select your device in RMS → Device → Manage Services and ensure that ‘monitoring’ toggle is enabled:
Without access to the device, it is hard to say what can be the issue here. I would suggest checking the device if possible. For example, check what error is displayed in Services → Cloud Solutions → RMS. Maybe it will be enough to restart the service/device, maybe you will need to add a DNS server if the error says that it is unable to resolve a hostname, for example. If the device is in a remote location and it is hard to get access, I would suggest contacting your designated sales manager or reseller from whom you have purchased the device. This way, you will be able to provide the necessary information over a private communication channel and the RMS team will be able to look into the issue from the RMS side. This way, you will be able to know where the issue is coming from.