Shape Map - unique map keys

Hi,
I realise this is a late response and hopefully you have it sorted now but if you don't or someone else reads the thread, this might help.
Whatever field you pull into 'Location' for the shape map is the one that Powerbi uses to link to the map. I don't know how it chooses which field in the shape map to join to but there must be something clever going on. It probably has an algorithm that makes a best guess on data type and/or field name.
Obviously in this case 'county' is not unique in the shape map and so multiple counties get selected across the USA.

I tried with the supplied data set and pbi file. I added a new column combining state_fips and county_fips and padded the data where necessary to match the template XXYYY where XX is state fips e.g 05, 11 and YYY is the county fips e.g. 001, 012, 107.
We know that the us-albers-counties map has fips code in this format and that it is unique. I then pulled the new column into the 'Location' field of the shape map. This was only partially succesful. I added a slicer for State for testing and saw that not all the states were displaying appropriately.
I found that this is because of an issue with the us-albers-counties map provided. Some of the fips codes are strings and some are numbers.  So Powerbi can't make the link.

You can solve this by either getting a different USA county topojson map with the fips code in a consistent format OR as I did, edit the map in QGIS to make fips a string , export it as Geojson, convert to topojson and add it in to powerbi.  Make sure that the fips column you added earlier in powerbi is also a string.  This works.

As an aside, the 'view map keys' feature for shape maps isn't working in my desktop powerbi.  The window appears then it shrinks horizontally to about 1cm width.  Probably a bug.

Doug