TFT display board will not work with other devices connected to SPI

Hi I am using the TFT screen together with Arduino Due and it works fine communicating with the display. However, when I tried to connect another device on the same SPI-interface the communication failed, but if I disconnected the MISO pin from my other device it worked fine. What I have noted from the TFT screen schematic is that the buffer 74LVC1G125DCK will hold the MISO pin low since the enable signal is always connected to gnd. What is the reason to this solution?