When started, the Code Coverage Browser uses the internal code coverage data (that is, the data for files that have been loaded with code coverage) if there is such data. You can revert to using this at any time by using the menu command Code Coverage > Use Internal Data .
The statistics that are displayed when using the internal data are computed once and are not updated as the data changes. If more statistics have been collected, update the data using the Refresh toolbar button 
or
Window > Refresh
.
When opening a file from the list, the tool updates from the current counts, and then opens the file, so both the tool and the coloring correspond to the state at the time you open the file.
LispWorks IDE User Guide (Macintosh version) - 13 Sep 2017