I'm using the non-commercial (free) version of TeamViewer (v15).
The list of My Managed Devices shows two devices: ELITEDESK and LENOVO. I can connect from LENOVO to ELITEDESK but if I try to connect from ELITEDESK to LENOVO I get the message 'Either your partner isn't connected to the internet or your partner's TeamViewer is running yet' which is clearly untrue as I can connect the other way.
Any help would be appreciated.