JP Tucson, AZ
I'm big enough to admit when I do dumb stuff...
So early this morning, I worked a bunch of FT4 & FT8 & everything worked fine.
I then did some experimenting for about half an hour, & after that I went back to working FT8 - or rather tried to!
Something wasn't right, for try I as I did, I now couldn't seem to 'hear' or decode hardly anyone! Where I had been decoding a couple dozen signals on 40m, I was now seeing only a few.
It took me about 5 minutes to realize that I had minimized the wide-graph & after I brought it back up, I saw the issue in that I was only seeing a small portion of spectrum, it took another min. Or so to recheck my frequency, check, usb, check...
Scratching my head, it suddenly dawned on me the cause... I had been playing with CW for a bit, & while I returned the radio to usb... I had forgotten to re-select the wide ssb audio filter setting (instead of the very narrow cw filter)! Which is why I was only seeing a few signals in that small region.
Duh! It helps to run in upper sideband with the wide audio filter to match.
Recheck & double-check all of your setting after changing operating modes...