Ugh - had a day from hell. Short version - NEVER, EVER have confidence in the basic commonsense, intelligence & human decency of your societal peers when sitting on a jury in a very important court case.
Dropped car off at local Hyundai dealer - explained issue/s. As I avoid them like thee plague (going to the dealer) I also asked if they could check if any vehicle firmware needed updating, specifically the DCT (as I was led to believe this was still the OEM version and had been improved). Also had a rego check done as thats next month or so.
End of day came back after my civic service, advised the Left rear wheel speed sensor was shown immediately by their system to be the issue. They checked it, appeared fine to inspection but tested and it failed so they replaced.
$496 for this alone (not including the rego check).
They claimed 2hrs labour for the job - suffice to say I found it a tad exhorbitant but after having a car reduced to 1990's level of safety for a month (no ABS, no ESP etc) and on the back of a horrid day I just went on my way putting it down as a lesson why I don't go to the dealer. Have attached the invoice with old school redacting - just incase it helps others that have a similar issue.
It appears the sensors are available for $60-100. You may be able to simply install and then clear the codes via a battery disconnection etc - but DYOR.
Lil annoyed overall as a 2018 car should not have ABS sensors failing already.......