A couple of days later, so I thought I'd provide an update.
Things got really strange on the weekend. My VOIP service was really screwy. I could receive calls, but could not make outgoing calls. At first I did see the connection between this issue and the router firmware, but after some frustration I guessed it was related. This was just another factor pushing me to do the M&M config, but I was hoping to wait until the end of the week. (moved my VOIP ATA to a different router, which I've wanted to do for a while anyway, and it is working fine so at least I can make and receive calls again. I use a router from my ISP as the top layer , then the RT-AC68U as my internal router with Wifi disabled, then a RT-N66U as a wireless access point)
In any case, I was on 384.11. I was unable to perform the Reset to Factory Defaults. It would go through the motions, but would not reset. I tried to downgrade back to 384.4 and again, it would go through the motions, but stay on 384.11. Frustration building.
Time to try the reset button on the back of the router. Push and hold until the power light flashed. No joy, settings were not reset. Did some reading and figured out this was in the emergency recovery mode, so ran the Asus utility (hard wired to my laptop after changing my IP etc), but the utility could not "find" the router even though the connection and everything appeared to be fine. Frustration building.
At the point where I can't load any other firmware, I can't do a factory reset, half the services are "screwy". Almost tossed the router, but instead did a number of hours more searching and reading and stumbled across a post that said to use the WPS button instead of the RESET button. Duh, come on, it makes perfect sense! Why didn't I think of that before! LOL
Ok, fresh day, fresh idea. Pushed and held the WPS button and got the fast blinking power LED (now I know what the fast and slow blink look like). Great sign! The setting were reset. Finally making progress.
Flashed back to 384.4 (just for fun), and started following the M&M process (for the most part as some things didn't apply to me). Reset the JFFS, reset to factory through the UI,.... rebooting when appropriate.
Flashed the 384.11 update. Rebuilt the JFFS partition, reset to factory,.... rebooting when appropriate.
Now finally the frustration level is pretty much gone. The router is on the latest firmware and I can actually change settings, perform GUI actions, etc. Let the manual config begin. NTP is also working properly now, at least according to the logs and date/time in the UI.
Wireless -> Professional -> Disable 2.4GHz Radio
Wireless -> Professional -> Disable 5GHz Radio
LAN -> LAN -> Device Name -> RT-AC68U
LAN -> DHCP Server -> IP Pool Staring Address -> 192.168.1.200
LAN -> DHCP Server -> Default Gateway -> 192.168.1.1
LAN -> DHCP Server -> DNS Server 1 -> 8.8.8.8
LAN -> DHCP Server -> DNS Server 2 -> 8.8.4.4
WAN -> Internet Connection -> Enable UPnP -> No
Firewall -> General -> Enable IPv6 Firewall -> No (IPv6 is disabled)
Configured my 2 x VPN clients.
Rebooted my network devices that needed new DHCP addresses and populated the network map mapping MAC to IP where appropriate.
Saved config files along the way just in case.
All good now. A big Thank You to those who tried to help. Sorry to turn out to be lame user and not trying a rebuild without being told. I have 35 years in IT and should know better but I've been updating the RMerlin firmware for years without issues using the saved config files.