ADF4007 PLL

Hello .;

I am using ADF4007 PLL in my application board. PLL loses lock when, I try to read either R or N divider at MUXOUT pin. What would be the possible reason/s?

Supplementary question:  Would it be possible to use ADF4007 to some configuration to deliver a lock detect Signal?

Thanks a lot for your time and help.

Regards

Mannam