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- Photostream only syncs photos over Wi-Fi, make sure you are connected to Wi-Fi to begin with.
- Photostream only syncs when the camera app is closed, ensure it is closed.
- Photostream only syncs when the battery is above 20%, try recharging the device
Try disabling photo stream on your device (settings > iCloud), restarting your device and then re-enabling photo stream.
Note: disabling photostream and re-enabling it will result in any photos that are currently in the photostream album on your device, that are older than 30 days old, not being added back.
Try turning photo stream off, then back on. Before doing so, if you have any photo stream photos on your phone that are over 30 days old, save them to your camera roll or you will lose them.
If your phone has stopped syncing other iCloud data, try deleting your iCloud account, then signing back in. (This only deletes it from your phone, not from iCloud. Your data will reappear on your phone when you sign back in.O