bd864344bb
.. when a userchart is embedded into an overview mouse events do not propagate in their entirety- as a result the legend widgets do not see MouseRelease (even though they see MousePress). So the click to show/hide when hovering over a legend item responds to the press not the release.
GoldenCheetah
About
GoldenCheetah is a desktop application for cyclists and triathletes and coaches, providing a rich set of tools and models to analyse, track and predict performance, optimise aerodynamics and train indoors.
GoldenCheetah integrates with most popular cloud services like Strava and Todays Plan, imports data from bike computers, imports downloads from any website like TrainingPeaks and Garmin and will also connect to smart trainers using ANT+ and Bluetooth.
GoldenCheetah is free for everyone to use and modify, released under the GPL v2 open source license with pre-built binaries for Mac, Windows and Linux.
Installing
Golden Cheetah install and build instructions are documented for each platform;
INSTALL-WIN32 For building on Microsoft Windows
INSTALL-LINUX For building on Linux
INSTALL-MAC For building on Apple OS X
macOS and Linux: 
Windows:
Official release builds, snapshots and development builds are all available from http://www.goldencheetah.org