As seen in the attached screenshot, notice the events that are shown as busy. This issue is caused when the Google calendar settings are set to only show free/busy for the public side.
Go to Access permissions for events under the Settings for the calendar to fix. There switch it from See only free/busy (hide details) to See all event details. After making this change, the event's name will be displayed instead of busy. This can be done by the Administrator console if you have a G Suite account (school).