Clicks and Pops when Waveform displayed

Hi, 
When playing audio in SF18 there are clicks and pops ONLY if the waveform is displayed. If I minimize the file window it plays fine. 

SF10 which I still have installed plays all files fine, even when zooming in and out of waveform. 

ALL other audio programs play fine while showing waveforms. It’s ONLY a problem in SF18 when the waveform is viewed. 

Tried video card settings, hardware acceleration, etc.

Thanks,
~Frank
 

Sound Forge Pro 18 Build 21 64-bit

intel 17

64 GB Ram

SSD drives

Windows Home 11