Mac OS Txt Messages "Not Delivered" Message!

MacBook Pro (13-inch, 2016, Four Thunderbolt 3 Ports)

macOS Monterey v. 12.7.6

iPhone 13 mini

iPhone 17.6.1

Messanger 14.0 (6000)

This is very frustrating because it "used" to work just fine before either of my devices got updated, Urgh :( !!!

Because "I" do not want my txts to be kept in history for anyone other than on my device, I do not sync my iPhone messenger with iCloud, period! Great Feature! This has worked for a decade!!!!!

While the following few months (May - September 2024), Mac Messenger has either worked or not worked where by I am able to txt someone or not!

1. When I open Mac Messenger, my txt from my iPhone are no longer sync (Please do not tell me it is because I have iCloud sync off because this would be a lie)
2. When I txt an iPhone recipient I get the dreaded "Not Delivered" message
3. When I txt an Android recipient I get the dreaded "Not Delivered" message
4. This all started with PDF files a few months ago to where we are at now!

Funny enough, I Tested today:

1. I was able to send a txt message from Mac to an iPhone and it worked
2. I was able to send a txt message from Mac to an Android and it worked, although "I did" get the "Not Delivered" message WTF???

Android recipient told me that they got the message!!!