When I was changing weapon illusions using the crafting tab (new GUI), my Conflag Staff had 4 seemingly identical basic (white) illusions.
I was opening chests, favoriting, upgrading, and salvaging for about 15 minutes before checking the illusion menu on a whim.
I saw no issues when looking at the illusion part of the weapon inspection window.
Do we really need two different ways to apply illusions, by the way? I guess the crafting tab one is convenient to quickly check what illusions you have without having to switch weapons.
Tangent aside, I started the game while typing up this report to check again, and the ‘problem’ has resolved itself. Posting it anyway since it’s technically a bug.