sim card number transferred but still receiving texts

Hi,

I have an iPhone 5s, not VoLTE capable. Early this year AT&T said my SIM card would not work much longer, I assume they meant the shutdown of the 3G network. As a Google Voice user it only made sense to get an Android phone. I plan to keep the iPhone 5s & use it on the house W-Fi.

I now have a Pixel 6 with a new 5G capable SIM card. The carrier deactivated our old SIM card on the iPhone 5s & activated our new SIM card on the Pixel 6 (or moved our phone number to the new SIM card). I left the old SIM card in the iPhone. Two factor auth was working on the Pixel & I assumed all was good.

Well, today my neighbor texted me & it came to my iPhone, not the Pixel. Normally I have folks text me on my Google Voice number, but this neighbor got ahold of my SIM card cell number a long time ago & apparently doesn’t feel like changing it in his contacts. He found a problem, perhaps I should thank him. I texted him back from my iPhone & he received it. So, I guess that means the 3G side of the SIM card is still active? I then texted him from the Pixel, he received it & texted me back, it again went to the iPhone, not the Pixel…

The cell number that has been moved to the Pixel 6 still appears under iMessages (Facetime too), I think that is the issue.

So, I have been messing about in the settings:

Removed my SIM card number as Trusted Phone Number in Settings > account name > Password & Security. Added my GV number as new Trusted Phone Number.

Now under Settings > Phone there is no associated number.

However, iMessage is waiting for activation & looks like it is waiting for the cell number that is now on the Pixel. My Apple ID is active under iMessage > Send & Receive, shouldn’t iMessage activate using my Apple ID?

I am thinking the cell number now on the Pixel should be removed entirely from the iPhone 5s & I should only be using my Apple ID. Does that sound right?

Could it be that my old SIM card was not fully deactivated? Guess that is a question for the carrier.

Or should I just remove the SIM card from the iPhone 5s?

Thank you