New calendar not syncing

I’ve got several calendars and have just created a new one but it’s showing I’m available all the time. I’m using Google Calendar and have checked it is the right calendar. Events are busy, Timezones are correct.
All other calendars are fine.
Any other ideas?

You can check Units per slot. If this is set to more than one any busy event will use up one unit and allow more bookings during a time slot.