ID 505439 - Viewer temporarily turns black when disabling track items

Problem summary
Viewer temporarily turns black when disabling track items
 
Customer reported version
nuke.13.1v3
 
Customer reported platform
 
Steps to reproduce
 
1) Open Nuke Studio

2) Import two 4K QuickTime files and add them to the timeline above each other, like \\netldn\netshare\support\4Pete\footage\Bambo.mp4 and \\netldn\netshare\support\4Pete\footage\Site_2_PondTrees.MP4

3) View the timeline then disable the top clip by pressing D, sometimes the Viewer will turn black. If you press and hold D, you should see it flash black between falsign between the two images.
 
*To increase your chances, set the viewer to 1:1 and set the output resolution to UHD_4K, press it many times rapidl, or try clearing cache
 
Expected behaviour
For the clip to be disabled and the clip below to show
 
Actual behaviour
The viewer sometimes turns black when disabling clips:

 
Workaround
Unknown. 
 
Reproduced by support
This bug has been reproduced in:
Nuke Studio 13.1v3 - Windows 10, CentOS 7, macOS 11 * much worse in 13.1 than earlier Nuke Studio versions
Nuke Studio 13.0v1 - Windows 10, CentOS 7
Nuke Studio 12.0v1 - Windows 10, CentOS 7, macOS 11 - regression
 
Unable to reproduce bug in:
Nuke Studio 11.3v6 - Windows 10, CentOS 7, macOS 11 * Viewer very occasionally turns black, but much more rare than NukeStudio 12 or later
 
Earliest version tested
Nuke Studio 11.3v6 - This issue doesn't appear to be as bad in this version and has regressed