Hi. I no longer use VPN on the router (I only have it on my PC and TV). If I have time, I'll go ahead and do the factory settings. So far, I only work on a dirty update. On the other Side , I don't think I'll figure out where the problem is if the problem reappears. Fortunately, I know how to go back. Just upload a backup that I will make before the factory settings ...Sounds to me like you have a tiger by tail w/ that solution. Dirty upgrades can lead to all kinds of problem in and of themselves. Esp. when you make that big a leap. New features like the VPN Director are likely to have issues given its a major change in how routing policy is handled, w/ significant changes to nvram variables, code execution, etc.
So while it's nice that things are working the way you want, I can't help but wonder how long the party is going to last before you discover other issues.
Anyway, if it's working for you, great!