Multi-Highlight inconsistency / Bug

Morning all

I have a query regarding the user of multi-Highlight mode and Multi-Select (Ctrl-Click Select)

We have a present, which has multiple discovers with different dimensions depicted as graphs, if I open up the menu and enable multi-highlight, everything works as expected, I can click on Dimension Category,  Day of week and then Hour of Day and it will filter down correctly showing me sales for that specific cat on that day of the week at that hour. 

It feels like a bug but i am happy to be told im doing it wrong, albeit that suggest a UX issue.

Using the multi-highlight option on the following dashboard.

Here we have ambient, Sunday and 10AM selected which correctly becomes...

If i use Ctrl Click on Ambient we get the following, ambient is highlighted, the rest have filtered correctly
 

 If i then Ctrl Click and highlight Sunday, Ambient correctly shows 5K, Sunday has however changed to 10.6K

 If i add the final filter and ctrl click 10, firstly it selects 7 instead of 10, then changes everything, if i click 13 it will select 10!
The selected products do not reflect what i selected regardless.