When I upload a new activity and share it with someone who does not have an account it will show the distance units only in kilometers. This happens on the old and modern interfaces. I know in the old interface there is a link on the top right corner that will say "Switch to Statute" or "Switch to Metric" no matter how many times I click on "Switch to Statue" it stays in Metric every single time. I tested this on Google Chrome, Mozilla Firefox and Internet Explorer and all have the issue.
I am having same problem but in my case it is showing up metric when I post to Facebook. I have read through many posts and there doesn't appear to be a fix for this yet. I am assuming Garmin people look through these froums?
