Even though this issue was reported earlier (in version 1.23), and declared resolved in the 1.24 beta, it now seems to have returned. Upload of observations with a previously taken image attached does not upload. The upload circle appears, fils halfway, and then stops. After some time the message “waiting for upload” appears.
I have been having the same issue. Version 1.26.11 on Samsung S8 running android 9. It seems to work when on Wi-Fi and when I don’t close the app, but even then it is slow. If I accidentally close it or have too many queued up to upload, the observations stop at the halfway mark and refuse to upload like OP said.
Just today I made 10 observations, six of them synced once I was on Wi-Fi, but one is now stuck on the half circle and preventing the others from uploading.
The next time this happens, please send us log files from the app. To send log files, go to the About tab in the app and tap three times on the version number. You will then have the option to email the log files to us.