Set spanfreq failed

Quote from xPanda on 25/06/2021, 08:42

I set device to iqreceiver , then set device/receiverclock to 92MHz , set main/centerfreq to 108.0e6.

then set main/spanfreq to 100Hz 、300Hz、600Hz   or bigger than 64e3 Hz  , get data Ok.

but set main/spanfreq to 1.0e3Hz、10.0e3Hz、50.0e3Hz....   get data  fail.

so how can I  get data when set  freq between 1.0e3Hz and 64.0e3Hz ?  thanks