Not sure what triggers Animate to stop using keyboard shortcuts. Might be after a browser preview, but shortly after the app will crash.
Preview in the browser usually has rendering error such as missing art. Restarting the app seems to recover where I left off.
Running Edge Animate 2014.1.1 on OS X Yosemite 10.10.3
Previews in Chrome 42.0.2311.135
Sometime damaged preferences files can cause crashes, errors, and other unexpected behavior in Edge Animate.
Follow the instructions below to restore preferences to the default settings.
if this doesn't help then please let me know.