Data Paired with DIGITS - No SMS on second phone

I just signed up for a Data Paired with DIGITS line so I can use my main phone number on TWO phones. I went through the process of getting the line, downloading and activating the eSIM on my second phone, etc. Incoming calls ring on both phones and I can make calls on both phones. I can *send* texts from both phones and they are good -- all messages coming from my main number regardless of phone used. However, INCOMING text messages are only received on ONE of my phones.  The second phone does not receive any texts

I have called T-Mobile support countless times over the past few days and spent more than three hours with their support trying to set up and now troubleshoot the service. I am reaching my limit. Has anyone else had this issue and (more importantly) does anyone know how to fix it?

The rep I spoke to this morning somehow "reset" both lines and I was able to receive one text on both phones so I know it is possible. After that, it went right back to only the "main" phone receiving incoming messages.

Many thanks in advance for any help!!!