Well, I tested the wallet with firends. I confirm that the wallet has a conflict with openvpn.
Have you tried changing default port settings of VPN ?
I have noticed when VPN starts up I get 50+ connections attempts while only 10 are connected.
After some 10 minutes everything seem to be normal, 30+ connects.
Testing now VPN with non default ports, simply added 40 to the default ports 920 = 40920
50+ at start up are gone and it now shows normal behaviour like other qt clients.