Sonic: Renegade Mac OS

Switched from legacy DSL to FTTN two weeks ago. Started using ovpn.sonic.net from Mac OS X 10.10.5 (Yosemite) last week and it works fine except when the Mac goes to sleep. When waking from sleep I get the message:
This happens whether or not I disconnect from ovpn.sonic.net before the Mac goes to sleep. The only way to recover is to restart the Mac. Logging out and back in does not fix it. I haven't yet tried to flush the DNS cache but one clue is that after waking from sleep the Mac seems to have lost its identity, i.e. it's hostname gets modified into a random string of characters. I have this Mac's networking setup to use a static IP and I'm pointing to the OpenDNS servers 208.67.222.222 and 208.67.220.220 rather than AT&T's DNS servers.
Anyone else see this issue?
Thanks.
UPDATE (2/26): I did a little testing:
1. I noticed that the PACE 5031NV had its DHCP server passing out IP addresses that could collide with the fixed IP's I give a number of the machines on my network. It's currently served range was far below the actual addresses I use, so I don't actually suspect there's a real collision at the moment. I changed the DHCP server range to what my previous routers had used. Unfortunately, this did not effect the OpenVPN behavior reported above.
2. I used OS X Terminal to check the hostname before and after sleep. No issue there. However, after waking from sleep and then attempting to connect to ovpn.sonic.net, the hostname is set to unknown123456789 (the number string is made up for this example). Therefore, it's the OpenVPN app that's corrupting the hostname. Note that a successful connection does not change the hostname.
FOUND THE PROBLEM:
The OpenVPN app is indeed corrupting the hostname, but it's doing so when it exits. After a reboot, the 1st connection attempt always works. But if I disconnect and attempt to reconnect, it fails repeatedly.
Will SONIC send the OpenVPN app writers a bug report? Or should I?

I have tried to look up this answer on my own; but am not finding any definitive answer.
From what I can tell, SonicWall does not offer their GlobalVPN Client in an OS X-compatible version. Since this program is essentially free-of-cost to end-users who use it to connect to their firewalls at their office, I am wondering if there is another program that I can use that will allow me to connect to the SonicWall at work that is also free of charge.
It would seem the onus of this responsibility lies with SonicWall but repeated calls to their support and sales team yield very little usable information.