The only way I can find to force Sourcetree to use my correct author information on commits is by using the "use alternative author" option. However, after every commit this selection resets to "use default author".
Why is my "use alternative author" selection not persisting?
An alternate view of this question would read:
"Why does the default author information in this selection override the author information configured everywhere else within Sourcetree, forcing me to rely on the 'use alternative author' selection for accurate author info on my commits?"