Hi Gav. I'm on my hols so recalling this rather than checking a setting in my obs PC but the triggering of the Unsafe mode may be happening because the driver loses connection with the CW, bringing the CW into an unknown state which triggers an Unsafe mode.
I had this occurring the first few times I was using my CW because I played around with the frequency duration of the read times (is it set to a default of 120 secs or some similar value?). I seem to recall this setting is in the dialogue box which pops open when you click on the connect symbol in the sequence window.
Check that it is reading 120s.
HTH
Barry