How to apply Conditional Formatting to ensure it updates when using slicer to filter data

Hello,

I have a pivot table with a large amount of data and use a slicer to filter. The data has conditional formatting applied based on different targets for each column.
I have attached an excel file with basic information.
Class room no. in the columns and each each class room as a different target.
When the target is reached for the period conditional formatting changes to green and when not reached is red.
when all the class rooms are visible the conditional formatting is fine, when the slicer is applied the data is filtered and the conditional formatting does not apply to the filtered data correctly.

Any advise would be appreciated. google failed to help.