Calibre-Web error trying to upload .mobi

I’ve been trying, unsuccessfully, to upload a mobi file to my Calibre-Web instance. I tested that I can upload an epub just fine, so uploads in general are functional. I’ve set the logging level to DEBUG, and the below snippet shows me checking the version of Calibre-Web, then trying to upload a file.

I’ve noticed that the file makes it into the “Unknown” directory, but the Calibre-Web GUI shows “Oops! Selected book title is unavailable. File does not exist or is not accessible”.

Does anyone have any thoughts or ideas to get this working?

Thanks!

[2021-10-05 21:27:22,087] DEBUG {cps.updater:303} Stable version: {‘version’: ‘0.6.13’}
[2021-10-05 21:27:22,399] DEBUG {cps.updater:575} Updater status:
[2021-10-05 21:27:56,037] DEBUG {cps.uploader:315} Temporary file: /tmp/calibre_web/d6d065d09f6f8d34f50ce6c3c0a89af5
[2021-10-05 21:27:56,100] DEBUG {cps.helper:373} Moving title: /tmp/calibre_web/d6d065d09f6f8d34f50ce6c3c0a89af5 to /books/Unknown/GIDEON_THE_NINTH_MOBI (38)/GIDEON_THE_NINTH_MOBI - Unknown
[2021-10-05 21:27:56,313] DEBUG {cps.services.worker:72} Add Task for user: john: <cps.tasks.upload.TaskUpload object at 0x7fe8d7be0ac0>
[2021-10-05 21:28:43,285] DEBUG {cps.web:1808} Oops! Selected book title is unavailable. File does not exist or is not accessible