I have an iPhone and in certain situations it will take more than one picture with the same timestamp. The two I can think of are taking HDR photos (where the phone takes a normal photo and an HDR photo and saves them separately) and when taking a burst (where you take a bunch of photos in quick succession, pick the ones you want to keep, and save them). In both of these cases, multiple photos have the same timestamp when measured down to the second. I looks like Plex will only upload photos if there isn’t already a photo in the library with that timestamp (down to the second), causing photos to get missed in the upload. Dropbox (my previous solution for getting photos to my computer) handled these by adding “HDR” to the end of HDR photos and “-1”, “-2”, etc. to the end of burst photos that are within the same second.
I couldn’t find this reported elsewhere on the forum. Can you look into fixing this, or do I need to post it somewhere else?