Hello. I have yellowing edges and tips happening on my more mature monster leaves suddenly and I am noticing that other leaves are starting to have these white hardened spots/edges. Is this a water, fertilizer, or fungus/insect problem? Is there something I can do to stop my other leaves from being affected. this is an indoor plant in Southern CA. Thank you

Hi plantmama, welcome to the NGA. I am afraid I can't help diagnose your problems. I actually made it a policy to not try and do that anymore from photographs, mainly because, there are so many different growing conditions that people have, and so many different ways that they treat their plants, and so many different things that it 'could be', and when you can't actually see all that and see the plant in person, its really only guesswork.
My growing conditions are most likely 100% different from yours, I don;t have these issues with my Monstera or any other plant generally, so I am not comfortable putting forth opinions. Perhaps someone else might be.