*** Fixed (for me anyway) ****
Still have not heard back from support on this, but it was a week before Christmas so not surprised or unexpected there. I have been jumping through hoops and knocking myself out on this. Reinstalled the driver. Played with buffer settings constantly. I even bought a a pricey Furman power conditioner and plugged everything into that. Was not the issue. Grrrr. I unplugged everything from the laptop except the interface and my monitors. Still happened with this "bare bones" setup. Man, I getting so frustrated that I was ready to throw down on an RME or something even higher end.
Anyway....
Here is the MAGIC CURE (at least for me). I bought my Dell XPS just for music production. It's a beefy laptop. Core i7 and 32 gigs RAM. 2 TB SSD. Should have all the power needed to drive a small studio. Then I remembered something. Heh. This is a laptop. There are power optimizations in the BIOS to optimize the battery (even beyond what is available in Windows.) So I looked in the BIOS and sure enough there is a performance tab. Playing with this seemed worth a try.
The settings that FIXED EVERYTHING for me was C-State (under the performance tab on my machine, but yours may be in a different location.). DISABLE this feature! What it does (according to info in the bios) is disable CPU cores when not in use, and then reenable them when the OS needs them. This happens very quickly but apparently it is enough of a hiccup in the kernel threads that this manifests as audio pops in the ASIO driver.
This is a low-level power management feature added by Intel. I suppose it is like driving a a V8 and having the vehicle turn off several cylinders when they are not needed. Ahem.
At any rate, this explains why mucking around with driver settings, or Arturia's mixer app fixed the problem for a while. It woke up the CPU enough that the clicks and pops went away (for a while, but then would always come back). Not anymore. BAM! All is well and works as expected.
I see this post has more than a few views. So really hopes this helps someone else, especially the OP. Please fell free to ask any questions if needed.