>>2892596>Fungus threadAgain, it's not fungus. "threads" like this are exactly what happens when lens elements separate.
Pic related is an example of lens separation. Look at the very similar threads.
I know for certain no fungus was involved here because I accidentally destroyed this lens myself because I'm an idiot (used far too much cleaning fluid on a minuscule spec of actual fungus, and it leaked into the lens group).