Calculated column being cleared when loaded to powerbi.com
I have a calculated field that comprises of the town a property is in with ", England" appended to the end to enable me to map the number of properties in each town on a Map.
This was working fine until recently, but it now appears that this field is being cleared (or not calculating), I'm not sure which, when I load the report to powerbi.com.
The visualisation works perfectly OK in the Desktop app and I cannot recreate the problem there, so it seems to be something to do with the Service.
Is this a known problem (a quick search with my favourite search engine doesn't bring anything up) or can anybody give me any pointers as to how to debug what is going on?
I have tried renaming the field from Country (in case that caused a problem) and I have dropped an extra visual onto the report which shows the list of towns and a count, but that is clear by the time the report is viewed on powerbi.com.
Could you enter some random data into a excel file with same table structure as the SharePoint table, then get data from this excel file and use the command which can cause this issue to repro it? If it can be done, you can share the excel file which contains the sample data to me to repro it locally.