EX7300 - all lights on, but not connecting

I've been using this extender for about 6 months with no real issues. All of a sudden it's not connecting, despite all the green lights on. The router is working, and has been unplugged and plugged back in - did not help. On my device WiFi list, the ____5GEXT (mesh extender's WiFi) still shows up as an available option, but when I try to download the firmware update, or now any time I try to connect  to http://mywifiext.com, I get a page that says: You are not connected to your extender's WiFi network. (How can that be?)

Even tried plugging the mesh extender right next to the router, along with my laptop - same result. 

Using a MacBook Air, so no ethernet cable to connect with.

I've even tried doing a factory reset on the Netgear mesh extender to restart and re-set up the system, but this doesn't even work.

I'm using MacOS Catalina, 10.15.1.

Not a tech person - very frustrating. 

Help is appreciated.