In the recent update to version 4.74, there is a bug in the custom stride length. It defaults to custom stroke length related to wheelchair mode, but there is no way to turn off wheel chair mode.
In settings/user settings/custom stride length, I get a message to turn off wheel chair mode. I have a Vivosmart 5 synced to Garmin Connect. Wheel chair mode is not available on Vivosmart 5. I have no way to turn off wheelchair mode.