Just an update for anyone that is interested.
During my search across the internet for this issue, I came across a few other people with the same issue. I also found a couple of posts on here where the OP had asked a similar question although they did have a much earlier version of the firmware (4.
. I also discovered another pilot had reported the issue to Funke as well.
I had a reply from Funke this morning and there first suggestion was moving the PilotAware unit a greater distance away from the transponder. They said that due to the Funke being a class 1 transponder and putting out double the power of a class 2 (i.e. Trig TT21), it is possible to overload the DVB-T antennas. I have had no difference at 2m or 30m and I have never had an issue with a Trig TT22 which is also a class 1. They also said they were obtaining a PilotAware unit over the next week or two to test the issue.