You're not going crazy, it's simply a Google Maps Timeline bug

The Google Maps Timeline allows you to see the places you visited and the routes you took to get there. It is private and only you can see it. However, there is a problem with the Timeline according to(via ) from users. For some unknown reason, some of the location data isn't showing up on the Timeline leaving gaps on the graph. Some report that all data on the timeline dating back before early May 2020 has disappeared while some are seeing months to years of data go missing.
Actually, the data