With the many scripts you have installed you need to investigate individual/custom options. Like YazDHCP has it's own save/restore, for example. Basic settings save/restore works between firmware versions and even routers, but you can't rely on saving more advanced configurations in newer Asuswrt-Merlin and restore them on older firmware with no such settings available or even used.
I don't know how you run that many scripts on AC86U with known software bug. This router locks up from time to time even built-in TrendMicro components.
Has anyone else observed any "stuck" commands on their router since upgrading to 386.x? Below is a frequent occurrence of the wl command getting stuck being spawned by conn_diag (this process was created at 4:10 AM). But I've also seen it happen with some nvram get commands (I once had Skynet...
www.snbforums.com