So this is a feature rather than a defect.
Regarding subcategory icons being shown on the main page in 1.01, I noticed an issue when a category icon is used w/o a font awesome icon.
tl;dr
Custom category icons aren't shown on the main page for subcategories If a font awesome icon is also used, it is shown instead.Request use of a scaled down subcategory icon, or the ability to use icon + font awesome, but not have font awesome shownn on the main page.
https://github.com/NodeBB/NodeBB/issues/4381
ghost created this issue in NodeBB/NodeBB closed Subcategory icons on the main page #4381