I've been having the same issue with one of my cameras, and it turns out for me that adjusting the timezone in the photos app to align my camera's photos with my phone's photos, does in fact destroy the app's ability to share those photos. Oddly enough, this isn't the case with every camera I've taken photos with where I manually adjusted the timezone for in the photos app — just one of my cameras. I'm not quire sure what I'll do about this. Apple's latest version of the photos app is broken, and I really don't feel like adjusting some many thousands of photos to my home timezone since the times are strictly incorrect at that point. (Keeping the correct time and locations for all of my photos has been very important to me. I would deeply appriciate if apple would address this issue, since I'm no long able to share many-many photos I've taken)
[Edited by Moderator]