Be careful when following any of these outside third party guessers. They are trying their best to make a guess about serp volatility. Unfortunately there are so many different factors impacting the serps that it is hard to separate normal flux from formal scoring changes. SEMrush is one of many companies that tries to track serp volatility. If you compare it with the other serp trackers you will see often the trackers do not agree on volatility.
I am not a big fan of micromanaging the serps. Google is making literally hundreds of changes to their algo every year. They average more than one change a day. To keep it interesting they often roll them out in batches to make it harder to reverse engineer. IMHO worrying too much about the individual stuff can distract you from the broad direction. By taking care of the big stuff and moving in the right direction, it often resolves many of the individual ranking influences.
If I were to pull out my crystal ball and give some general predictions on how best to make Google happy, I'd say get your mobile pages presenting well, pay attention to your backlinks from mobile pages (vs desktop pages), speed up your pages, switch to https. That should be enough to keep most webmasters busy for a while.
@seoskunk Ok, go ahead and present your evidence. Show your data. Display that documentation.
But please don't present a guess even an educated guess as fact without real evidence, data or documentation. Too many websites are struggling out there. We need to be careful not to accidentally misrepresent things and possibly mislead people. Fair?