Media not playing over LTE 3 questions

Video and audio files playback only over WiFi (using a different network) but not over LTE. Even small files.  Photos load via LTE but 3mb files take about 25 seconds to load.  1) Where exactly is the block and can I remove it (I’ve checked my iPhone settings and can find nothing that might be blocking LTE transfer) and 2) why is there such a delay in transferring photo data? Email photos load almost instantly. If this is a Network speed matter 3) how best can I test and speed up my Network?    iPhone 5/ 2Tb Mycloud/ linksys n router.  many thanks.

Have you checked security settings or firewall to see if it’s blocking the connection?

Please be aware that the speed on the data plan would affect the overall performance while playing files.

Thanks for your reply.  No firewall problems or blockages.  LTE is faster than the WiFi I’m using so there’s no problem there.  My suspicion is that AT&T is blocking it but I cannot get a definitive answer from them.

I phoned the concierge service and restored the System Only under Utilities/Settings.  That did the trick.  Many thanks to WD for their help