New Verizon G1100 Router > Can't set up Echo

I obtained a new Verizon G1100 router. Everything in my home reconnected to the router successfully except for my Echo.

I spent an hour on the phone w/ Amazon. I rebooted and reset the Echo, restarted the router ... nothing.

However, I DID connect to my neighbor's WiFi succesfully. So, that points to my router. There must be a setting or incompatibility with my router and the Amazon Echo.

Does anyone have any ideas for any router settings that might be adjusted to get the router to connect to the Echo?

Thanks.