Hello ranger_roux,
Thanks for using Apple Support Communities, it's great to have you here.
We know how tricky it can be when messages are being sent to devices you're not expecting them to appear on. The good news is, we have some great resources to share with you that we think will do the trick. The first thing we'd start with is checking to see if the old devices are still signed in to iMessage or if your Apple ID accounts are still receiving messages on those devices. This would be possible even without an active SIM card as iMessage will work over cellular data and Wi-Fi as well.
On one of the old devices, navigate to Settings > Messages > Send & Receive and check here to see which Apple ID accounts or phone numbers are listed. If you see your Apple ID, go ahead tap that account to deselect it. Those messages should no longer be received by that device.
However, if you're noticing that the messages are specifically coming from the incorrect telephone number as you mentioned, then it's possible that you may have set up an eSIM on the old iPhone that needs to be erased. This could potentially cause your number to still be associated with the old device. Here are the steps to erase the eSIM if that is the case: How to erase the eSIM on your iPhone - Apple Support
We hope that this information is helpful.
Have a great day!
