My Orbi RBR750 router stopped connecting to the internet

OK here is what I did.

1. Confirmed the modem was still working by plugging an ethernet cable from the modem directly into my laptop (with the laptop wifi off). Internet was available – so the modem was working properly. Then I disconnected that cable.

1. Connected my phone to my laptop through a USB cable and set the phone up as a hot spot to get internet access.
2. Connected an ethernet cable from my laptop to one of the 4 spare ports on the Orbi router.
3. Connected the modem to the Orbi’s yellow port.
4. Now my laptop can see the internet (through my phone’s hot spot) and the Orbi router with its direct connection.
5. Cleared the cookies from my browser.
6. Factory reset the Orbi (this is one of two resets as you described).
7. Went to 192.168.1.1 from my Google Chrome browser and got into the Orbi setup page. (I had trouble getting to the setup page but after several attempts, I was able to get in each time.) I set up only the router the first time (said no satellites). I added satellites later - which you basically just plug them if you move them close enough.
8. Changed the address pool as you recommended.
9. Reset the Orbi a second time as you suggested.
10. After this second reset – Voila! The Orbi connected to the internet and came back to life!!
11. I made the wifi name and password the same as they were before so everything reconnected without a hitch.

I’m so grateful for the help! Thank You! Thank You!! Thank You!!! Still a Netgear fan!

Now that it's fixed, what do you think caused the failure?