Echo Connect, Ecobee 4 and calls from unknown numbers??

[ftarz]

I've got an Ecobee 4 thermostat with Alexa installed in my house. A while later I installed an Echo Show 5 with an Echo Connect at my mother-in-law's house.  Since my mother-in-law isn't technically savvy I configured the Show 5 with my Amazon account.

I've noticed that the Show 5/Echo Connect combination doesn't play well with caller-id information. Both outgoing and incoming calls are unknown numbers. But I need to check if my mother-in-law is paying AT&T for caller-id service. My Ecobee 4 does show my cellphone number if I tell it to make a call.

Now whenever my mother-in-law gets a POTS call at her house, my Ecobee 4 announces that I have a call from an unknown number at my house.

Is there any easy way to fix this? Is there a way to configure the Show 5/Echo Connect combination to do caller-id?

Do I need to create another Amazon.com account for the Echo devices at my mother-in-law's house?

Thanks.