This can happen, I've had it happen 10 mins before the program finishes. Its down to the server timing out or if the stream has come to the end. Make a note of the link used and just use another one. Also to keep an eye on the memory on your box and clear cache weekly. Also if your T8 has the kill apps button use that to kill them.
Also on the T8 on the main menu press and hold the menu button on your remote and a rocket should come up and clear some memory to. You can also change the back ground too.
Dave