Multiple website (not mines) DR crashing

Hi,

I have a website with a DR that went from 29 to 0.9 in a month (was at 29 for 4 months).

I have a client that had around 100 referring domains. Last month, I did a clean up to remove every domain with DR below 30 (there was 5). I just checked tonight and I found out 21 below DR 10

I just wonder : how? Is there an update or something I missed?

Regards

Ahrefs make some changes
You can read it on the blog: http://bit.ly/2FYh8zC

Ahrefs make some changes