Update on this: after troubleshooting with live chat they sent me a replacement stick. First day using it and the problem is exactly the same. Think the problem must be in the interaction between the stick and router, the only thing that has changed...
I'm having the same issue. I've tried a software update and multiple factory resets but the freezing is still going on. Only happens watching live sport on my stick, not on other devices or on demand. Anyone had any luck finding a fix?