Thanks for the fast response!
Yes - it's my laptop screen. And I keep magnification/scaling set to 250% nearly all the time unless I drop the res to 1080p (and turn off scaling), which I do for various apps that don't scale well or when using Remote Desktop or VMWare Horizon to connect to Windows 7 machines at work (as 7 scales horribly).
The laptop is an EVGA SC17 1070G, with an NVidia GTX 1070 and 17" 4K (3820 x 2160) non-HDR (unfortunately) G-Sync display. 4K is overkill at 17", but it was the only option in the closeout deal where I picked up this laptop.
I've attached the log. I presume there's no personal info in it? If there is - even if there's a chance - please download it then remove it from this post.
I suspect this issue just got missed when scaling improvements were made elsewhere in the app. I just updated to Windows 10 version 1903 build 18362.267 so checked again, but it still isn't scaling correctly.