Autosave for draft comments, evaluations and emails is a local event (computer/browser-specific) and the information is stored in each member's browser for approximately 7 days. It could even get wiped earlier if any significant changes happen to the computer/browser or if you clear cache, etc.
Workable can’t retrieve autosaved information as those are locally stored and they never reach our servers/database.
If an autosaved item is still stored in your browser you will find it filled out by navigating to the candidate's profile and clicking the button to add a comment or evaluation (depending on the action taken). Make sure you submit it to prevent its deletion in the following days.
To ensure no data loss you could consider submitting any comments/evaluations right away, even though they're not complete. This way you should be able to edit them at any time and add more details once you are ready to submit the final comment/evaluation.