[The Weed]

Known issue, search online. Here's how I fixed it:

Ran into this after I passed the deadline to roll back. Note: my Windows Updates are permanently disabled in Group Policy Editor (only available with Windows 10 Pro) so I manually updated to 1903. However, since I don't stress PT very much, the pops were only showing up rarely and randomly. When I got around to running LatencyMon, it hit RED after a few minutes on dxgkrnl.sys and ntoskrnl.exe.

Searched online, found a few solutions, uninstalled a few Windows KB OS Updates, made changes to my BIOS - some of my BIOS optimizations had, for some reason reverted to default - made sure my NVidia GT640 card had the latest drivers, disabled a bunch of Services, did the Preferences and Database dance (thanks for Thrasher Steve) and checked my Sound and USB Power Management optimizations.

Ran LatencyMon and now I was over 900 for both and in the green, but still too high really. So I imaged my OS drive and then installed the latest updates for Windows 10 1903, which turned out to be KB4505903, released July 26, 2019, bringing W10 1903 to Build 18362.267 .

After all the BIOS and Windows optimizations/checking optimizations and graphics card driver and the Windows OS Update, I ran LatencyMon for an hour and 51 minutes. Much better results as seen. Not sure what resulted in the much better LatencyMon report, but I'm back to where I should be. As always, YMMV.