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

2. If your price planner is set up correctly, navigate to the Settings page of that property by selecting Settings from the menu bar.

3. Scroll down to the section Short breaks, and check if you have a value in the field Allow late availability 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 into the future.
7 days in the case of the screenshot above.

If you don't want to allow this, delete the number, set it to 0 and click Save.