Texting myself, my phone number is green since ios16 update
I have followed all the other advice, I logged out of my Apple ID, I've turned iMessage on and off, I've checked and unchecked "send and receive from this number."
If I text myself using messages on my Mac or my iPad, messages to myself are still blue.
When I text myself with my phone (which I do to send reminders to myself with Siri while driving etc), my texts to myself go as SMS messages.
This started with the ios16 update last month.
iPhone 12 Pro, iOS 16