At the Magellan driver settings, check if the checkbox USB reader is ON and ‘Infinite Series’ is selected at the dropdown and disable Allow simulated reader device to prevent it from possibly connecting to some reader simulation instead of a real device.
Otherwise try: Open Magellan, connect there, somewhere in the instrument settings (an icon with a blue cog wheel), there is a reader instrument selection where you can select and connect to your specific reader in Magellan. After connecting, close Magellan and open and try again in FluentControl, perhaps it remembers that setting about what is your specific reader from Magellan (but I don’t know for sure).