Just one of stems have leaves that have a white film on them and I’m not sure why. I never owned any plants till recently so I’m not really familiar with them. I did some research and moved the plants and it’s done very well for last 6months. Also, some of my leaves are very shiny and some are very dull.
It may be as simple as water deposits from water splashing unto the leaves. This residue can be cleaned from the leaves with a damp clean cloth.
Plants can become dusty over time and will benefit from a cleaning. You can wipe the leaves or even give them a shower.
Place the plants in your tub and gently shower them with water. Allow to drain and dry.
If the problem persists it could be caused by a fungus or insects.
Neem Oil is a good and safe treatment for both issues. It is also safe for people and pets.
Here are some links with more information.