I am not sure if this was discussed before.

This is what happens.

When I start the console, if the frequency is with offset (for oscar-100 rx) my waterfall has no visible signals even if it is set to the correct frequency.(there is white noise present) 

When I change the frequency to something else  and return back to the first frequency, everything works.

I recorded a screen capture at https://yadi.sk/d/sz8KuHXGRdksww

In the first seconds, it is not visible but I am selecting rtl-srd radio..

Then you will see a spectrum without any signals after I change the frequency.

Regards

de TA2NC