I moved your post to #bug-reports.
Can you please send your log files to help@inaturalist.org?
To do so, go to About, tap Version three times, and follow the directions there.
For me, the problem is that the send icon is too small for me to hit exactly with my finger. The app interprets my attempts to hit send as a “click away” and so pops up that message. If I am extremely careful and hit the send icon just right, I don’t get the pop-up message and the comment goes through, but since I find that very difficult, I get the pop-up more often than not.
Thanks, Amy and Melody, so this should be a feature request (bigger button) instead of a bug. I did not place it in bugs cause I also found out it worked sometimes…