As of a couple of weeks ago something happened with my photo gallery. I have always been able to use my photos in the photoshop app and be able to upload my photos to places like Costco and Walgreens to buy prints and now suddenly the files aren't supported. The only work around I have found is to screenshot and then upload that. I have tried everything I can think of to fix it!
You can see what format the pictures are stored in. Open a photo in the gallery and slide the picture up to get details. For sites like Costco and Walgreens the jpg format is probably the best.
Check Camera settings -> Format and advanced options to ensure that "HEIF picture" is off
You can also try Camera settings -> Reset settings.
