1. Go to Properties > Edit > Go.

2. Scroll down to the Short breaks section.
Depending on the options selected there are different update buttons.

By default you should see the button labelled Update Short Breaks.

If you are using the options to auto-calculate the percentages from the weekly price, you will see the buttons Update prices for this property and Update prices to all enabled properties. Use either of them to update the price planner(s).