~Fix
Yeah to fix it I just went through the instructional guide on another thread (https://forums.macrumors.com/threads/1805510/) to set it up again and it finally switched from iMessage to Text Message for SMS Texts. And definitely very strange that there are no clear instructions.
I had some issues with this also. I just made sure that I selected the email address that I use for my apple id on both my mac and iphone. I prefer just having my phone number selected, but it seems that you need to have the matching email addresses selected on both devices. My phone number is also selected and I think I may have rebooted both also just to be on the safe side. It is strange that there are no clear cut instructions on how to set this up.
Yeah to fix it I just went through the instructional guide on another thread (https://forums.macrumors.com/threads/1805510/) to set it up again and it finally switched from iMessage to Text Message for SMS Texts. And definitely very strange that there are no clear instructions.