I'm not one to quote (or even listen to) Katy Perry, but her "adage" of "you're up then you're down" is quite applicable to the rank fluctuations seen on the Google SERP in the recent past. There was some downright bizarre movement on the SERP in August... on multiple occasions... There have also been changes to how Google extends 'Search Journeys' (and how Google promotes its own shopping experience), the schema supported by Google, scroll to text highlights, etc.
I'll be diving into all this and more! This is the September 2020 edition of the SERP News!