This is true. I've also noticed a significant difference in Moz's DA and Ahrefs' DA. My website Mzcurioso has a DA of 15 on Moz, but only 5 on Ahrefs. I recently came across this article discussing Moz's methodology: https://searchengineland.com/moz-domain-authority-case-against-431732. I'm not sure which of the two platforms provides the true authority of my site."
