TFP401: what`s wrong with the output clock can't change with of tfp401 input clock change when HDMI to RGB signal change application ?

dear sir

     l use the TFP401 to achieve the HDMI to RGB change ,below is my schematic, u_sill1161 is TFP401 module board, U8 is TFP401 module schematic , when i

change the RXC_P RXC_N to 75M, the ODCK is 150M, when l change the RXC_P RXC_N to 50M, the ODCK is still 150M, the output  image is fine ,but ODCK

output is always 150M, what`s wrong with my setting ?the internal PLL of TFP401didn`t work now, can you help to resolve it ? I didn`t use i2c; I change the resolution of HDMI source；

 my HDMI source is PC ; l confirmed the frequency with the oscilloscope