When making manual changes to your calendar, this creates scheduling exceptions for Task Events, Habit Instances, and Smart 1:1s. You can can reset those events, and Reclaim will attempt to schedule your calendar back to its original state based on your Reclaim settings.
To reset your policies
From your Google Calendar, click on a Habit Instance, Task Event, or Smart 1:1 to show the Habit or Task details in the add-on panel.
Scroll to the bottom of the panel to Scheduling Exceptions.