About a week ago I did a backup / reinstall / restore as part of some QoS troubleshooting in another thread. I found that OVPN stopped working after this process and instead of creating a new topic here, I had a private messaging session with @bonnietwin. In my attempt to not convolute another thread or start a new thread without context, I decided on the PM route. Now that we have solved the topic, I am posting it here in public so any future users with a similar issue might have a resource to reference.
We determined that there was missing information in Services->OpenVPN. I was tempted to blow away my server key and start over, but I had over 20 users that I would then have to recreate and reinstall configs for. We instead decided to try restoring my backup again. This took a 3am trip to work so as not to disrupt business operations. I started the restore process again, taking my time. This time, the restore brought back all OVPN data and users could use it again. We hypothesized that perhaps I didn’t wait long enough before clicking out of the restore screen to restart the hardware, or maybe there was just some other glitch. But in the end, simply re-restoring brought in the rest of the missing data.
Anyone in a similar predicament is advised to do this before taking more drastic steps.
Thanks to Adolf for his patient and persistent help.