Emma Nzioka, a Kenyan performer and DJ known as Coco Em, was looking forward to the Terra Sagrada festival in Cape Verde for nearly a year. Some of her favourite African artists, such as Boddhi Satva, would be playing.

But Nzioka did not make it to the festival last month, or out of the country, for that matter. At the check-in counter in Kenya, she was told she could not board her flight unless she bought a return ticket with the same airline (she had one with another airline) to “prove” she would return home. Although Nzioka was going to Cape Verde, she was transiting through Amsterdam.