Domain Change behind Drop in DA from 49 to 9?

[SEO-SMB]

Hi,

We have recently gone through a domain change and thought we had done this by the book.  We 301'd the old site extensively  and optimized our new site as best we can.  All done with the help of a leading agency.

However our old site had a DA score  of 49 and checking our new site's DA almost 3 months after the changes its scores 9!

Furthermore with rankings 2-3wks after the change we saw small drops (1-3 positions), 3-10 weeks saw more gradual slides but remaining page 1 for most terms. Currently some core terms are slipping back to page 2.

I have the below question on this and would like you to get your opinions and views.

1. After a well planned domain change would its be expected that the DA score would remain in the same region or is a drop like this normal?

2. Is the domain change the most likely cause of this drop or are there other factors that may cause this?

3. What is the best approach for trouble shooting this situation?

[ThomasHarvey]

This could possibly be due to: https://moz.com/community/q/10-14-mozscape-index-update-details

See the following snippet: "Second, many PA/DA and other metric scores will look very similar to the last index because we lost and had problems with some metrics in processing (and believe that much of what we calculated may have been erroneous). We're using metrics from the prior index (which had good correlations with Google, etc) until we can feel confident that the new ones we're calculating are correct."

[SEO-SMB]

Thanks Thomas, yes i guess this may well be the reason.  We had the new URL live for a period of 3-4 months before we made the 301 of the old site so the score of 9 may be from the new site being scored before the actual change is my assumptions... I've checked other software to now like Majestic and Ahrefs and scores in these are similar to pre domain change.