I've just downloaded and run the trial version of Vegas Pro 21 and added some MXF files from a Cannon XF305. On playback the sound is just hash. Can provide more data if necessary.
Yes, there are some audio issues, for the time being, with the Canon MXF format.... Search the forum where you will read further discussions regarding this.
Thanks guys. I checked the windows sound settings and Vegas seemed to have changed something. When I restored defaults all was well. If it happens again I know the fix now. Thanks again.