If you click the Omega icon on the toolbar, it shows recently-used symbols but they are too small on Windows (200% DPI) on a 4K monitor.
Steps to Reproduce:
1. Run Writer on Windows
2. Click the Omega icon
The favourite characters are too small that they are almost illegible.
They should be bigger, like on Ubuntu (see the attached screenshot).
User Profile Reset: Yes
I will attach a screenshot. On the left is Windows, and on the right is Ubuntu 20.04.1. On Ubuntu, Writer's version is 6.X, but that was the latest version available (updating did not give me 7.X). On Ubuntu, the symbols are big and legible, on Windows, they are not.
Created attachment 168248 [details]
*** This bug has been marked as a duplicate of bug 115634 ***
Sidenote for OP, looking at your screen clip if you select an SVG icon theme (Tools -> Options -> View) you will not get the pixelated icons that come from scaling the PNG icon set beyond the ~125% range. The SVG icons are scaled and saved to cache as PNG. Clear your user cache when changing UI scaling to get a clean set.