Why UBX 160 gain not work (for RX and TX)

[stackprogramer]

Hi, in my USRP x310 I used a daughterboard ubx160, but in Gnuradio gain is not effect... gain 0 and gain 100 show the same signal...for FM station it can not show any signal How can solve my problem?

Gnuardio 3.8.1 UHD 3.15.1

thanks in advance