Thanks for the reply Peter.
I am not sure what's going on. I have lost most of my tv channels and when I was trying to reset my Fetch and TV settings the 'poor internet speed' message came up.
I have NBN fibre optic cable to my house so I shouldn't have internet performance problems.
I replaced my tv aerial and now have great reception at the tv, however if the feed is through the Fetch box, while it is better it still gets random pixilation and some channels drop in and out. All online channels work perfectly.
First up test without any splitter involved (i.e. one aerial cable from the wall to the fetch unit)
Online channels use the internet, not your aerial.
Its up to you if you want to request a replacement Fetch box. (It's free as its a leased box)