router not seeing devices on upstream router

I also thought I'd note a few other things that may help other folk with similar issues:

1. Sorry, I lied in the first post.  I thought I had everything on the same subnet but the router had switched the local subnet back to 192.168.1.x.  This is, no doubt, the fundamental issue since the NAS is on 192.168.0.x.  On the previous router I was able to limit the upstream DHCP to IPs .0.x where x is limited to 0-199 and the local DHCP IPs to the same .0.y where y is 200-255 so they shared the same subnet. The RAXE500 seems to have it a hard limitation that the local subnet must be different then the upstream network (you get an "IP address conflicts with WAN subnet" error if you try to force them the same).  You can constrain the addresses to a subset of the full 0-255 but it still requires the local subnet to be different.
2. In my research I found some posts suggesting AP mode doesn't perform as well as full featured mode.  However, it appears to be working great.  I got the RAXE500 for the 6G performance to use with an Oculus Quest VR headset in wireless link mode which requires a LOT of bandwidth.  My prior 2.4G Cisco was terrible/unusable and I was forced to use the headset wired for desktop games (which is very annoying).  However the wireless mode works great with the RAXE500 with no perceivable stutter or performance loss in both AP mode and normal mode.
3. The literature I found says you will lose a some features in AP mode including the guest wifi account.  However, the guest wifi account is still available.
4. I tried the advanced ("old school") method suggested here but only managed to lock up the router forcing a factory reset.