I recently did a clean install of Windows 10 build 1909 64-bit, and then downloaded and installed XnView MP 64-bit successfully. After I installed the program, I registered it to open image files. It now shows up as my default photo viewer under "Settings" -> "Apps" -> "Default Apps", which is what I want.
However, when I open the Start Menu, only the icons for Microsoft Store apps—not non-Microsoft Store software—become XnView MP "PNG" icons. Here are some screenshots that show what I'm talking about:


You can see that in the second image, the application icons for Firefox and AdGuard—software that isn't downloaded from the Microsoft Store—are displayed correctly. Yet the other three are apps downloaded from the Microsoft Store, and their icons aren't displayed correctly!

How can I fix this problem (without uninstalling XnView MP)?