wspr-x spectrum

Hi Folks:
I've seen this a couple times, and wonder if anyone else has.. At some point, The spectrum still scrolls, but shows nothing for hours, not even a base line, but the decoder is still decoding signals.. I pull the radio out of the mic jack on the computer, plug it back in, and the spectrum starts working.. That's all I have to do. Scratching my head.. de KB2MEN