Datagrid with calculated and formatted columns

My datagrid has calculated and formatted columns, so I cannot bind my datagrid directly to my collection. I therefore inserted a “Formula” in the “Init value” zone of the “Specific” part, for example like this :
if(context.item.data?.[‘nbCourses’]>0,round((context.item.data?.[‘nbPlaces’]*100)/context.item.data?.[‘nbCourses’],) ,0)+“%”

This principle is in place on each of my columns, but they are only loaded when the formula for my column is defined and are not refreshed. I must not be doing the right thing, can one of you guide me to the right approach please ?