I want to know why my crash events show unsymbolicated stack traces even though I expect debug information files (DIFs) to be available.

You’ll need to confirm that the debug information file was actually uploaded and that it was uploaded before the event was reported to Sentry.

You can check if the debug information file was uploaded by searching on your Project's Settings -> Debug Files.

Note: The file size limit of an individual DIF is 4GB.

General information on debug information files can be found here. Information on using the sentry-cli to check, find, upload, etc. debug information files can be found here.