Version: 55.0.2883.59
OS: Windows 10.1

1. chrome://tracing
2. hit Record button
3. choose "Manually select settings". nothing is checked.
4. check some categories in "Record Categories"
5. press Record, then Stop, OR just cancel the dialog.
6. hit Record button again.

Expected: The same categories from step 4 are checked.
Actual: Every category under "Record Categories" are checked.

Workaround: Switch away from Manual and then back. i.e.:
7. Select a different radio button (e.g. "Web developer")
8. Select "Manually select settings" again
Now the checkboxes are indeed populated correctly from the state in step 4.