Porting my old AT&T number to MJ. Any issues?

[Amik]

I just installed MJ Plus to test it, with the intention of later porting my good-old AT&T number that I've been using for decades.

I know of MANY horror stories about AT&T customers who switched from AT&T to Comcast, and LOST their old number in the process..... So I want to know if there've been any issues with this that you guys know of... Thanks.