iPad not receiving Android messages

iPhone 14 Pro Max, iOS 17. My grandson has an Android phone (and an iPad I gave him years ago), when 17 came out, texts to him started going to his iPad, not his phone. Fixed that by removing his email address from his contact card (NOT ideal), but now texts to him get to his phone but responses no longer show up on my iPad Pro, 12.9 also on iOS 17. I’d prefer to answer texts on my iPad, bigger screen and I’ve an external keyboard. The iPad does receive WiFi calls.

So, what is the issue and how do I fix it so his messages show up in both places as they used to? Thanks!