qTox Message never sent when both parties are actively online.

[OscamSatUser]

Brief Description

OS: Windows7
qTox version: Sender v1.17.6 / Receiver v1.17.4
Commit hash: 54345d1
toxcore: 0.2.13
Qt: 5.12.12

Both parties are utilizing windows7. One party running qTox version .6 other .4

Observed Behavior

This is the second time this has occurred. A message was issue from one client, and the other client NEVER receives the message until the receiver restarts Qtox. Even though Qtox is running and NOT crashed. I took over the receivers computer and clicked on the user within qTox that should have received message and no message was visible. I then restarted qTox, and message was received within 5 seconds.

Expected Behavior

Message should have been received by qTox.

Additional Info

There is a active VPN connection in our network that connects 192.168.1.* with a remote VPN connection at 192.168.5.* The message was being sent from 1.* to a user on 5.* ... The VPN was active and working as i was able to remote connect to the machine on 5.* I am not sure if qTox message is going through open internet to send message or through vpn.

Please let me know what i can do to maybe catch more information the next time this happens. Being its happened twice now, and both parties leave their computers on 24/7, I am confident this issue will keep occurring. In the mean time, i will update the receiver to the latest .6 version so both parties are running exact version.