There is an inconsistency in the way cadence is displayed.
On the activities summary that lists all of my runs in a table with time, distance, average run cadence, etc, the average run cadence is showing what appears to be my real cadence divided by two. For example I have average cadences listed at 80 steps per minute.
When I examine the details of any activity, the cadence there is shown properly, at about 160 steps per minute.