I have a re-occuring problem with the Slack app on my phone. When in the photos app on my iPhone and I click on the share icon and then select share to Slack, one picture will usually go through and post to Slack. When I try to share a second picture to Slack, using the same method, it rarely completes the posting. It just goes back to the Photos app with the photo still selected. My phone is fully updated as is the Slack app. This behavior happens when I'm on LTE, or Wifi and on battery or plugged in, with new photos and with old photos from several days ago. I have tried rebooting the phone and it doesn't help. I can't identify any pattern other than the first attempt usually works and subsequent attempts usually fail. Any ideas on what else to try?