With most search terms shifts in impressions and position change gracefully over time, then there are the ones which seem to move in mysterious ways.
One such example is the roller caster impressions of search terms which have a predictable pattern, a dead giveaway is the predictability of which day the spike will occur.
While the serp rank jitters just a bit, impressions peak on a given weekday. Given the search term there was no way this would be attributed to actual user behaviour.
Odd patterns can also be seen in the serprank of specific words, as the image displays the example search term was on a seesaw ride until the impressions finally flickered out.
These 2 examples might indiate that the Google Seach Console suffers from manipulation as well as dubious ranking algorithms when roller coaster and spastic impact has an impact on search terms.
Perhaps Google algorithm changes will be a bit more controlled, the data will provide an answer moving forward...