SMS not being received - iPhone 12 to multiple Android users

Hello! I am presently experiencing an issue that is driving me mad! 🙃

My father has informed me he is not receiving text messages from me.

• He IS however able to see screenshots I send to him.
• SMS no, MMS yes to both him and a friend with an Android as well.
• I’ve confirmed the color of all messages going out are green, and that they always confirm Delivered.
• I text a iPhone 11 on our plan with iMessages off and it shows Delivered on my end but doesn’t show up on her end.
• That iPhone 11 is able to text Android’s confirming it’s just happening on my line.
• Group messages as far as I can are working fine.. Baffling.
• Confirmed calls to and from another another working
• Confirmed Android call yesterday before I did Network reset

I've restarted numerous times, and reset the network settings. I'm not sure what else to try.. Any ideas?

BONUS EXTRA BULLETS:

• On my Mac, the Messages app is not showing my messages in or out after my Network reset.
• A key difference between my Mac and iPhone experience: while iPhone says Delivered on every non-delivered message, Mac Messages at least has the common decency to say ‘Not delivered’ on them after a minute or two.
• iMessages working between Mac and iPhone on Messages for Mac

Sometime during the week before 09/24 I swapped my SIM from an older iPhone to the 12. I've had no problems at all up until last Sunday in to Monday, That's when I was first alerted to the problem.

This has turned in to a lot of stuff.. but this just feels so random, any help would be greatly appreciated.

Thanks for reading!