The history is not recording every action. This program is wonky.
I have been using LR since version 3. Never had issues till now.
Which version of Lightrom are you using? Is it up-to date?
Please backup your Lightroom catalog first.See How to back up catalogs in Lightroom
Then make sure Sync settings are not active
If that does not help.Reset Lightroom preferences following Resetting Preferences in Lightroom CC/6 | Lightroom Blog