VNA cables need to be considered as consumables, they will eventually break or the connectors become worn. There are many sources of flexible cables online, Amazon and EBay have many. There is nothing magic about the ones that come with the nanoVNA, they are just run of the mill stuff. I always mark mine so that I can return them to the orientation and port they were on when I did a calibration.
73, Don N2VGU
Donald S Brant Jr