It looks like they were unlucky in the number of chargers stops they went to that were either not working or were already occupied.
It does say that they didn’t want to use a 7kw charger because of the time it would have taken to charge it; perhaps it would have helped them if they had.
Most of the stories I have heard of people with electric cars are good, but most charge and drive from home. The motorway network has lots of fast chargers but they are not reliable in terms of whether they are working.
Given the uk wants to end the sale of fossil fuel vehicles in the next 10 years there will have to be a lot more investment in motorway charging spots if they are going to succeed.