Google Site Speed Insight:

Regarding fluctuations in page speed scores, Google states that it’s quite common to have the scores fluctuate irrespective of improvements made on the websites or not. Google page speed scores should be taken as a means for improvement but shouldn’t be considered as a final goal. Also, Google reported a Page speed bug in Feb’19 which had also caused lower scores.

Our web team tracks the page speed score on a daily basis for a given month and uses the average score in the Monthly report.

List of backlinks:

I’ve attached the list of backlinks as well lost referring domains for your reference. There are a total of 839 lost referring domains over the last 60 days. Although these backlinks might have not built entirely by us, they’re somehow gained naturally. You can focus on the most important one’s and see how you can regain them back.