2 Different Apple IDs w/same phone number
I had my phone associated with my two different apple id - in fact, I still do. Both of my iPads use Apple ID X, while my phone and laptop use AppleID Y.
And up until a couple of days ago my iMac (Late 2015) had Apple ID X and my phone number associated with it for iMessage, up until I moved my home directory to an external disk to free up space on my internal SSD running my OS.
So - why am I now getting this error that my number is associated with another appleID?
Why do I have two apple IDs? That's neither here nor there, the question is why was I able to do it before and now I'm not. So frustrating.
Thanks in advance for any help.
David