I'm pleased to report that the issue of URLs becoming not-clickable when moved to Values has been fixed. Not sure when the fix came through but in my current version (Version: 2.56.5023.942 64-bit (March 2018)) the URLs are now clickable whether as Rows or Values. Thank you MS Dev team!
Uh, ok @vanessafvg thx for the clarifiction. Two reasons - aesthetically having the URL in the Values area gives a dividing line between my grouping data and my actual values and as we have very little control over appearance it is a way of making it look better. I have simplified my matrix, URL is only one of the field values I have in the visual and they are grouped by the other two fields in the Rows area. That takes me to my other reason - functionality - as far as I can tell, in the matrix we group by items in the Rows area and our actual data values are in the Values area. Something tells me that the way I am trying to do it should be functionally correct. However I stand to be corrected if I'm not understanding it.
@vanessafvg thx for the link, I hadn't seen it before but it doesn't add any clarity for me sadly.
I know what you are saying, yes there is aggregation because of the grouping, however we are provided with textual aggregation tools = 'First' and 'Last' so I was hoping textual functionality may be preserved. In my case there is only one row of data in each group.
And having said that my data has only one row per group when I look at the two screenshots I posted it certainly does not look that way. It's getting late here so tomorrow I'll go back to my model and re-check that.