Amazon Prime Video/Fire Stick

Would appreciate if anyone has experienced issues streaming live tennis on a Fire Stick since the weekend, with constant pixellated /blurry video

I have been through troubleshooting with their online help and gone round and round in circles before finally getting a case ID today.

Never had an issue before and don't have a problem on any other devices on the same connection which leads me to think a software update has caused the problem on both my fire sticks.

When I join a stream/match it's very blurry or blocky for around 5 seconds, then it's like someone has wiped the mist off the camera lens and it's ok to watch (i.e acceptable and in almost HD) prone to occasionally blurry moments, every now and then, but nothing I can't put up with.

It was better yesterday and today, was only really an issue on Monday and Tuesday, not sure why.