Why isn’t the Google keyword data available for dates older than 3 months?

When you’re using the SearchEngineKeywordsPerformance Premium plugin, your Google Search keywords data are imported from the time in your website or app. Google Search Console API only provides access to the data within the last 3 months. Unfortunately older data can’t be accessed. But once you have setup the import of Keywords in Matomo (Piwik), we will keep your keywords data full history and over time you will be able to access your keyword data history over many months and years. Matomo helps you liberate your data and keep full control of it.

With one of the December 2020 updates Google extended the data availability for the Search Console API to around 500 days. If you started using the SearchEngineKeywordsPerformance plugin before those changes have been implemented (< 4.2.0) the first import might still have imported 90 days only. If you want to import older days you still should be able to do this using the manual import on console.