Rank-tracking platforms may have recorded ranking changes that did not represent a conventional shift in Google’s organic results. Research from Nozzle documented what it calls “poisoned” Google SERPs, result pages that appeared normal but contained substantially altered result data when fetched...
Source: [Dev.to](https://dev.to/alifar/google-serp-poisoning-may-be-distorting-rank-tracker-data-1cfj)