Looks like Google Timeline has been deleting peoples data? Discussed a lot in Reddit as well.
Consider @timeatlasapp as a replacement (+ more) for Google Timeline. You can also import your timeline data there for free! The app is free with additional paid features. Data is stored locally and in your iCloud, so no-one can delete it...
Inspired by @einverne, here is a picture of my coast-to-coast trip with my wife, dad @EKyrola and brother @timokyrola . It is from 2013, originally tracked with the Moves app, but imported to @TimeAtlasApp. All the walks in national parks, night bar hopping in SF with @artman (with some grainy night pictures as the phone cameras were not so good at that time - not posting), all the driving we did -- it is all there. I could also publish the trip as a webpage, but too personal to share in X...