Photos showing on iCloud.com, but not on iPhone

Hi,

I recently moved over to an iPhone X, but was having this problem before (I previously had an iPhone 6S Plus, which was only 16GB, so I thought the issue might fix itself when I got more storage) basically, my iCloud photos shows all my photos, but my photo library in iOS only shows about 300 of the most recent, and the more photos I took, the more it erased from the phone. I have turned off and on iCloud Photo Library and could not find any other solutions to try while browsing. Does anyone have any suggestions for me to try? Thanks