Did you ever get an answer?
It MON (or yoy, wow) comparisons use table calculations to compare the 2 months - when you filter out one of the months (i.e. select only one month) there is no data in the table for comparison - there are numerous examples of using parameters (v filters) or hiding a previous month so the display only shows a single month and a variance
suggest you search form MOM, YOY, on the forum
I will search for that . thanks