6600 pulsing on tune- Then no receive audio

I'm wondering if anyone else has experienced something like this. I keep my 6600 on 24/7. I'm running SSDR 3.3.33. On occasion (hard to replicate hence no support ticket yet) after being away I'll come home and all sounds good on HF receive. I usually do a quick tune just to check the antenna. Occasionally, the meters on SSDR show a pulsing out put and SWR. The internal tuner is bypassed and the display on my Palstar HF Auto tuner shows steady out put and no SWR fluctuations. When this happens it also kills the audio output. Signals show on the waterfall, no audio from the speakers. Shutdown and restart SSDR no change. Have to power off the 6600 and restart ro clear the fault.

I have performed complete shutdown, remove power for 2+ minutes, do the hard reset, reload my saved profiles and it still happens.

Suggestions welcome

73
Gordon
VE9GC