it’s an old std 330/332 problem/feature.
I once spent a couple of weeks in Darwin, on daily contract pay, touring around the Northern Territory in a company car with a Shell carnet. I was waiting for a UK registered 332 to be transported by Antonov from Aberdeen, reassembled and airtested by me with a British licence. They had fitted sponson tanks to it and the delay was because they could not get them to work.
Then there was no Antonov any more so I got totally bored and departed for more refreshing places.