one person not receiving my texts

Might you and your son be using the same Apple ID? If so, stop doing that immediately.

Here are things to do if you were using the same Apple ID:

• Thoroughly and completely cleanse your son’s iPhone as follows: What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support
• Help him set up his “new” iPhone. Help your child set up an iPhone, iPad, or iPod touch - Apple Support

Hi jpierini69,

Thanks for giving that a try.

Your son's iPhone might be in an area that doesn't have a good signal for data to reach through iMessage. Make sure he's in an area with internet connection, either Wi-Fi or cellular data.

I recommend your son turn iMessage off, restart his iPhone, then turn it back on. He can do that in Settings > Messages.

He'll want to check where he's able to receive and reply from on his iPhone as well. He can find that in Settings > Messages > Send & Receive.

If your son is still having issues receiving messages, have him contact Apple Support:

Contact - Official Apple Support

Thanks for using the Apple Support Communities.

Hi jpierini69,

It sounds like you are having trouble sending messages and I want to help.

Did your son recently stop using an iPhone?

He may need to deregister his phone number from iMessage if that's the case. Otherwise devices will continue to message him through iMessage when they should not.

Tell him to follow these steps:

Deregister and Turn Off iMessage - Apple Support

Thanks for using the Apple Support Communities.