Can't connect new oven to app on android

I made a guest wifi account on my router for 2.4GHz WPA.
Connected my android to that account.
Type in 4 digit number from oven handle
App tries to connect, then kicks me back to the 4 digit code screen with a “retry” button.
We’ve had this oven for 6 hours and we both hate it.
Customer service won’t respond to my questions.
If we can’t connect to the app, it’s getting returned under warranty.
Anything else we can try?

Wow. A question from 4 years ago an zero responses. Nice