Fungal infusion fertilizer?

How does it work? I can pour it on plants over and over again with no cool down like regular fertilizing has.

It seems that sometimes the plant levels up but most of the time it doesn’t.

Is it a random chance to level up the plant? Is it still locked out from leveling the plant based on regular fertilizer cool down? Do you pour it on and have to wait a few hours or days to see if it worked?

Does anyone know the actual mechanics of how it works?