G-Metrix Map location does not update/is frozen

For some recording sessions of Track Days with hours of video material on the identical round course laps, the red location marker is not moving at all. The other G-etrix data points display/update without a problem. Start/finish location/timestamp is set up correctly.

Changing the the start/finish location/timestamp does not seem to have any effect, either. I just cannot get the location marker to move.