Intermittent truncation of selection playback

[Sound22Card]

Intermittent truncation of selection playback. Better known as the 'ITOSP'..by no-one.
After selecting a section to erase, I always play it back to see if it contains an of the end of the last word or any of the start of the next word. About 50% of the time, approx. one third of the selected area plays and the cursor goes back to the spot it started from....sometimes the beginning of the selected area, but even if placed anywhere else within the selection. I press play and just get a blip of the selection. This applies to whether I am zoomed in or not. Obviously when zoomed in close, ...ANY selection will be just a blip. I understand that. Also, the Play being PAUSED isn't a factor. I just cannot connect the fault to any function, set or unset.
Stumped.

Win 10, multi-processor
All drivers up to date.