I have two indoor palm plants
plant 1 :
I water it adequately and keep it inside room with adequate bright light not direct sunlight, but the leaves are turning yellow and some places I see rusting spots along with some white fungus type forming in the leaves.
Plant 2 (areca palm) :
For this plant also I maintain bright light environment and water adequately once the top soil becomes dry. for this plant I see same white fungus and leaves are not turning yellow but having a oval rust formation.