Yes, I ran it with Sonar running the most complex project I'm working on, per the tech's request.  This file runs fine on Windows 7 with the 1.8/2.5.1 set at 3.0ms buffer.  I can get it to run without pops and clicks on Windows 10 with the 1.9b10/3.2.1 or 3.2.2 set, but I have to set the buffer to 1024 which results in a 10.8ms buffer.  I should probably reinstall the 1.8/2.51 set in Windows 10 and check Latency Monitor with that.
 
When running Latency Monitor without Sonar running, it says there are no problems.
 
I'm using most recent BIOS update that is available for my motherboard.

Let me know how you make out with the 1.8/2.51 set if you do the reinstall. Thanks.

I just received instructions to delete the Scarlett 18i20 from Device Manager, uninstall Scarlett MixControl, and install a file they sent me, 1.9b10.  Everything seems to be working correctly.
 
Help, About now shows this:
Scarlett MixControl 1.9.64.10
Driver 3.2.285 API 3.0
Firmware version 634.
 
I was never instructed to run Latency Monitor, but I'll give it a try now.
 

Latency Monitor seems to be higher than I remember it.  Once I started SONAR with a project, it shot into the red.  Again, I don't remember things being bad before.
 

I reinstalled the 1.8/2.5.1 set and was able to play the same Sonar project, but this time was able to get the buffer down to 3ms.  This is the same size buffer I used on Windows 7 with the same driver set.  Latency Monitor now said my system was suitable for audio...  Unfortunately, these are the drivers that became unstable for me on Windows 10 and prompted the need to try the beta drivers.  I'm going to do some testing to see if the other changes I made to my system made it more reliable.

When I open mine up is says 1.9.64.10.

riojazz
Latency Monitor seems to be higher than I remember it.  Once I started SONAR with a project, it shot into the red.  Again, I don't remember things being bad before.
 

Same results here riojazz.

I think I'm getting closer to a stable setup with the 1.8/2.5.1 set.  I went through the Black Viper Windows 10 services setup and it made a big difference.  I can use lower latency settings and everything is running smoother.  I think Windows 10 is loaded with things running in the background that can use resources that are needed for Sonar.

Good news. The latency settings and how you select them is what I liked best about the 1.8 Mix Control. Have you noticed, are you using less CPU as well? 

Yes, I'd say it uses a bit less cpu with the 1.8/2.5.1 set. 
 
What made the biggest difference for me was disabling unnecessary services, then solving the hard page faults I was getting.  The majority of those were caused by a Logitech Mouse software called Setpoint.  It was starting with Windows and running in the background.  Once I disabled it at startup, my page faults were greatly reduced, but there were still some.  The remaining ones stopped when I turned off Windows Defender.