Based on this comment, I suspect there might be a misunderstanding (due to my poor explanation, I suppose).
This is a known bug and there is no (reasonable) workaround. Rather than try to explain again, I was able to track down the old bug reports:
https://forum.inaturalist.org/t/error-when-submitting-id-or-comment-on-tab-left-often-from-previous-session/3753
https://forum.inaturalist.org/t/failed-to-save-comment/18941/5
If you’ve been bitten by this bug, please make a comment on the bug report so we can get this fixed. Thanks!