In order to ensure the Manager Server is functioning properly, make sure the following ports are allowed from your internet provider or in software like RTP MIDI:
TCP ports from 2020 to 2052 should be open and unused.
UDP port 5008 should be also open and unused.
Multicast should be allowed.
There are other software like Firewall and some Anti-Virus software that may block the connection of the server, detecting its internal traffic between the device and the control panel.
If the Manager Server is not running, you can check if your provider is blocking some of those ports by switching the computer network to a mobile hotspot.