If you can't find any external issues that might be causing the poor reception on the T4, it may be a problem with the T4 itself.
On some production runs of the T4, the heat sink cement on a set of 4 regulators that feed the tuners is also susceptible to breaking down, and the breakdown products can damage the circuit board around the regulators. This can lead to a variety of different problems (when it happened to my T4, the T4 was completely unbootable).
If that's the problem, you should get it repaired ASAP, because the damage to the circuit board is progressive, and can end up being non-repairable. The photo links in
this post are a good example of the problem The black stuff on the circuit board around the heat sinks should be white. On my T4, the cement was more a milk coffee brown, but had still done enough damage to make the PVR unbootable.
If you are willing to open your T4's case, you can check for discolouration of the cement. The two heat sinks are near the tuners, which are in the row of small aluminium boxes directly behind the antenna connections on the back panel. You can see the bottom ends of the tuner "cans" in the first and third photos in the Whirlpool post I inked to.
If you do open the T4's case, unplug it from the mains and leave it for 15 min before opening the case. The power supply has capacitors charged to over 350V when it is running. Leaving it after disconnecting the mains allows time for those capacitors to discharge.
If the cement is discoloured, you should get the T4 repaired anyway, even if the your reception problems aren't caused by the action of the thermal cement. That issue is progressive and is very likely to cause issues later. You can either contact Beyonwiz support ((02) 9603 1822 or
https://dtcsupport.zendesk.com/hc/en-gb/requests/new) or Mark Vasile (
http://www.decisivecomputersolutions.com.au/contact.html) about the problems. Mark posts as Warkus on the Beyonwiz forum.
I can recommend Mark: he's done excellent repairs for me on both an old Beyonwiz DP-S1 and on the T4 I mentioned above. You can see feedback from others on the Beyonwiz forum in
Warkus is a Legend!! (aka Mark).
As Ian-LS suggests, you may get more help on this problem, which almost certainly isn't an IceTV issue, on the Beyonwiz forum.
The differences between the exact channel names used by the broadcasters and those used in IceTV are normal. I think that IceTV regions cover areas where broadcasters use different names for the channels in different locations, but they all have the same IceTV EPG information, so the location part of the name isn't used in IceTV.