Double NAT on wired. Open NAT on wifi

FURRYe38 

Thanks for your suggestions.  On the initial setup of the Orbi out of the box, I did as you suggest with just UPNP and no other setting changes. The lengths I had gone to with WAN Open NAT Filtering, Port Forwarding, and finally Port Triggering were out of frustration when the NAT was continuing to bite me (pun intended),  Your last message though, prompted me to start over. From that, I have backed into the apparent solution and am embarrassed it was so simple.

I was so busy "fixing" the new parts of the network setup and so focused on the wifi vs ethernet symptom that I didn't look at the beginning of the chain.  I finally went into the Pace RG interface and saw that though DMZ+ was still set, the device that it was set up for was my old R7000.  Everything bar the NAT had been working perfectly, so I never considered needing to update the Modem/Router settings for the RBR750.  Two clicks later and a reboot of the Pace device and all seems good.  My Xbox Series X shows open NAT on both wired and wifi and my old Xbox One shows open on it's wifi now, too.  I'm going to leave things as they are with the WAN Open NAT Filtering and Port Triggering set for now.   If things continue to work well, then I'll start pulling out those provisions until I get back to the setup you have suggested.  I won't be using the Xbox One, so the multiple console aspect is no concern. 

I definitely fit into the category of knowing enough to be dangerous.  Hopefully, my stupidity will help someone else down the road.

Your suggestions were all spot on.  Thanks for the ideas and your quick response.