First off, on Mac is command+L the shortcut for selecting a line? If so, note the following…

If I select the following string using the shortcut noted above and then run “Convert Case: Title Case” from the command palette, the word “her’s” is ignored. The command only processes what comes after the character encoding (i.e., “is so cool”).

her’s is so cool

If I however manually select the string using my mouse, the command properly includes “her’s”.

This is different from the “Convert Case: Upper Case” command which runs just fine whether I select the line using the shortcut or by mouse.