I have 2x, exact same monitors. Different resolutions in coherence mode?

Sys. Info:
System/OS: MBP 2017, macOS High Sierra (10.13.5)
Version: Parallels Desktop (13.3.1)
VM OS: Windows 10 Pro (all latest updates)

I have two 4x monitors hooked up to my 2017 MBP. They are the exact same make and model, bought at the same time, and have worked fine.

Last week I created a new Win10 that I'm using for some client work. I have no clue why, but what I'm experiencing is that the two "desktops" for each display appear to be of different Windows resolution. This means, as I drag a window back and forth, the overall size gets larger or smaller as it switched desktops. This is quite annoying.

To be sure, I've checked my desktop size settings in the MacOS display settings and they both have the same resolution settings. I can go into the display settings of Windows and try to fix this, however, my guess is that when I reboot the machine, Parallels will just re-adjust them when I log in. Is there a Parallels setting I can check/set/toggle-retoggle to try and fix this? It's quite annoying.