Bending any kind of electrical cable, including coax, can cause internal breakage of the individual conductive strands that make up each wire (see attached diagram). A single strand breaking doesn’t necessarily stop the cable from functioning, but it does impact its ability to pass current by increasing the electrical resistance of the cable. Over time and with repeated bending, more and more strands will break until the current is too restricted to transmit power or data effectively. You may have encountered this issue with a personal USB cable for charging your phone, for instance. Think of it as bending a copper pipe back and forth until it breaks apart; at first, it may impede, but still allow the flow of water, but eventually the pipe breaks enough – or entirely – such that water can no longer flow freely through the whole length of the pipe.