Comment 20 for bug 991666

I've had the same problem for about a year, and now, I think, I've finally found the way to fix it (at least somehow).

Looks like in my case it was the same as in https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/991666/comments/16 (duplicate routes entries).

So what I've done.

- run `sudo route -n` before connecting to VPN and after
- found entries that were pushed from the VPN server
- found duplicate entry
- manually added all but duplicate pushed entries to routes (Network connections -> your VPN connection -> IPv4 settings -> Routes -> Add ...) and checked "Ignore automatically obtained routes" checkbox.
- restarted VPN connection

Since that all works just fine.

Thanks to @botevmg!