FYI - I've just came across this problem with my last two runs - no map download. I've contacted Garmin support and although they are aware of this issue, unfortunately there may no be a software fix in the foreseeable future. Here's what they say;
"Thank you for contacting Garmin Europe.
The issue you are referring to is something that we are aware of and are working hard towards a resolution, however, we do not have a timeframe for this to be completed as yet.
When the issue has been corrected, the fix will be released in a software update. This will be announced on your Garmin Connect account or on Garmin Express. If, at that point you require further assistance please contact us via our Contact Centre whereby we will be happy to talk you through it.
I’m sorry for the inconvenience.
If there is anything else I can help you with then please let me know. Alternatively you can search for a solution here: http://www.garmin.co.uk/support
Kind regards,
Ben
Garmin Europe"