EX7300 extender connection and log in issues

I purchased the EX7300 extender a few years back, then purchased another one (version 2) not long after.  Installed and everything has been fine. But recently, something changed (not sure what) and while v2 (firmware 1.0.0.146) is still up and running, I cannot get the original unit connected.  

Also, what ever happened that changed the status of the older unit also messed up my ability to use all of my smart home items (Alexa smart clock, Echo, Blink cameras, myQ garage door opener, etc).  

To top it off, now when I try to log into the Nighthawk app, it goes to the log in screen (admin), but my log in credentials no longer work!  I've tried using the default "password" and I've deleted the app and reloaded it to no avail.  When I try to go through the "forgot my password" process, it takes me to a page that says I'm not connected to the router's wifi (although I don't have a Netgear router).  That's been a dead end and I have no idea how to recover my access.  I'm completely frustrated.

This afternoon, I plan to try to uninstall everything and start from scratch with a new account.  Hopefully, it'll let me reinstall the 2 extenders so I can get my house back in order.  ANY suggestions would be appreciated.  I have Xfinity with the XB7 router.  A bit frustrated that Xfinity took away our ability to control certain things, like separating the 2.4 and 5 GHz frequencies, but that's one of the reasons I bought the extenders.  (Which is what I suspect is happening....my smart devices have been reassigned to the 5.0 band, which renders them useless).

Thanks,

Cheryl