Windows 10: Icons disappear after DPI change.

I have a laptop with a 4K display and DPI scaling set to 250% (default), and whenever I change this to any other value and restart to fully apply it all of the icons on the desktop, taskbar, start menu, in folders and basically everywhere disappear (except for some windows icons like Edge browser and Cortana).
Changing the DPI back to the default 250% and restarting makes the icons appear again but I need to change the DPI in order to use an external display without scaling issues and blurry text.

:)

 

Is there a way to force DPI scaling?

The native DPI scaling is already properly set. (Change the size of text, apps, and other items is already properly set to 250%.). Some applications, however, disobey this DPI setting. An application (ChemDraw) that I am using is "nominally" claiming to
be HighDPIAware, when, in fact, the icons are not designed to behave well in high DPI screens (somewhat dishonestly). Is there a way to "force" DPI scaling of an application without changing the resolution of the screen?

 

Blurry tiles on Start Screen

As said before, same problem on my SP2 - 125% dpi scaling, after nov update.

UPDATES:

1. I noticed that the same tiles that are blurry in tablet mode are
slightly blurry also in desktop mode start menu.

2. All of this happens also on my desk mate's SP3.

On both systems, the problem disappears with 150% dpi scaling.

Fix this please!!!