Understanding last_changed vs changes in log book

I’m trying to work out an automation for being away from home, using trackers. Anyway, while tinkering with this, I’ve tried to figure out why the “last_changed” property to my tracker doesn’t match the state changes I’m seeing in the log but instead just mirrors the “last_updated” property. What I’m seeing in the log is what corresponds to the real world, “last_changed” doesn’t. How can I get the value of the proper “last changed” that I’m seeing in the log?