1. Go to Properties > Edit > select Price Planner to the right of the property > Go.
Check that you have no orange short break line within your price planner. You should only have an orange bar appearing when you do allow short breaks.

2. If your price planner is set correctly then navigate to the Settings page of that property:

3. Scroll down to the heading Short breaks, and check if you have a value in the field Days prior to arrival to always allow short breaks:

4. If there is a value in this field, it means short breaks will automatically be enabled from today's date for the next x number of days.
14 in the case of the screenshot above.

If you don't want to allow this, delete the number and click Save.