Flux UI gets severely darkened if entered while JEI is on screen with a query entered in its find bar.

Not all queries behave the same:
"a" -> regular / have matching results
"aa" -> dark / have matching results ("naan")
"as" -> regular / have matching results ("glass", "cast", "splash")
"asd" -> dark / no matching results, red text
"ash" -> regular / have matching results ("splash potion")
"ast" -> dark / have matching results ("cast")
"ass" -> regular / have matches ("glass", "grass")
"lass" -> regular / have matches ("glass")
"rass" -> dark / have matches ("grass")

Only the main UI panel gets darkened, not the tabs/buttons at top.

Fixed in dev

Can't recreate

What plugins do you have installed? Optifine?

No, no optifine.
Seeing this in skyfactory 3 modpack.

Mine is completely darkened from setup and unable to use! :-/