iCloud Photos not downloading

Hi, so I recently noticed that some newer photos and videos are not being uploaded to iCloud even though I turned on “Sync this iPhone” in the iCloud Photos settings, so I tried turning off and on “Sync this iPhone”, and then a pop up said “iCloud restore in progress”, though it wasn’t restoring from iCloud. Suddenly, all photos that were uploaded to iCloud turned blank in my gallery. Then I tried to select “Download and Keep Originals” in the iCloud Photos settings, and it just keep saying “Syncing…” and it hasn’t changed since then. How do I download the photos and videos from iCloud to my gallery?