Cannot connect Rachio 3 to Verizon G3100 WiFI

Technical assistance needed. I’m extremely technology savvy.

Brand new Verizon G3100 out of the box. Brand new Rachio 3 out of the box. Absolutely cannot connect the Rachio3 to the WiFi. I have connected other devices to the Verizon router and they join no problem, the internet working fine on other devices. I have 4 bars, very strong WiFi signal on the iPhone standing at the Rachio 3.
Using the Rachio App on iPhone, when I attempt to join the Rachio to the wireless network using the guided process I get a message on the iPhone App that an unexpected error has occurred. Times out and never connects. The yellow light is flashing in sector 2 but no matter how many reboots of the WiFi router or the Rachio no luck.

I have tried a number of troubleshooting steps including

  1. Rebooting everything repeatedly and running the App process on the iPhone. No luck.
  2. Creating a Guest WiFi with a simple short password. No luck.
  3. Turning off the Firewall security settings on the Verizon router. No luck.

Need some assistance as I have a Rachio 3 at another property and had no issues connecting to the Verizion Fios there, but it is the Quantum router not the G3100.

Thank you,

Well, looks like there is an issue with iPhones running 13.4 (which I am). I searched everywhere and only saw this after I posted this technical support issue:

Guess if they get this issue resolved it will work, or I can find some other device and try with that.

@RyanB - the issue is only on the initial setup. There is a manual workaround posted lower on in the link if you have another device that has WiFi -

curl -k -X GET -H "x-api-key: SERIALNUMBER" -H "Content-Type: application/json" ""

and then another command after that.