GPIO inOut/Bidir using Qsys to read and write to the same port!

I am willing to connect the IDE2_115 to 24bit AD7760 and I want to write to the registers and read data from the same port. I used QSYS and once defined the GPIO port as bidir and I could only read the data, and by having inOut I could only write to the port (I mapped both export_in and export_out to the same inout GPIO pins ). whether to write 0 or 1 to the port at bidir mode the output voltage remains constant at 0.97V

any suggestion to have GPIO both input and output at the same time? Do I need an external pull up resistor array?