Update regarding the issue.
Turns out the fault mention is actually being driven by the front brake light pressure switch on the ABS module. The switch does not fully open circuit when the brake lever is depressed and retains a resistance value of around 2.7MOhms which in turn is brining in the fault on the TFT.
What is more concerning is that when I was in carrying out the test work I noticed that the rear brake pressure switch has a leak, not from the copper seal but actually right out through the top of the sensor. This leak became significant to the point of being a jet when a large amount of pressure was applied to the rear brake lever depleting the rear brake reservoir in around 5 operations. Obviously this has rendered the bike unsafe to ride.
With the bike being under warranty and with active road side recovery I was able to get the bike uplifted by the AA and taken to my local KTM dealer on the 28th of August for repair. Honestly can't fault the service by the AA, they were with me within less than half an hour of the initial phone call.
The dealer has now had the bike since then and they still don't have the parts required to carry out the repair (Part Number 28111051000 x2). The only interaction with the dealer I have had is when I have initiated it via phone or else otherwise I would have been left in the dark. According the KTM parts website which has since been confirmed by the dealer the parts are on back order until the 7th of November. I have asked if they had any other bikes in stock that use the same parts which could be used for donor to get my bike back on the road which could then be fitted with the new parts when they arrive but was told that they did not. I kind of find this hard to believe considering they have a lot of stock of various KTM and Husqvarna road and offroad bikes which appear to use the same parts but how can I argue this?
The thing is, I have my full bike test coming up in the next few weeks and now I have no access to a bike to get any extra practice/experience in beforehand. I am now in a scenario now where I could end up having my full license and essentially a 125 that I don't have my hands on that I would be looking to move on so I can get a larger bike. The bike is also due its annual service at the end of October so they may as well be carrying that out when it is with them. Other than this issue I have experienced here the bike is immaculate and has only covered 1600 miles.
I have really enjoyed getting out the 125 Duke and it originally had me sold on moving on to something like the 790 Duke as I love the look and styling of the KTMs, however my experience with my local KTM dealer with this issue has been far from great. The next closest dealer to me is over 100 miles away which would make it unappealing when getting a bike serviced every year. I think now this experienced has made my mind up for me and I will be looking at other manufacturers in the coming weeks when I look to upgrade to a larger capacity bike.