I bought a Monstera Deliciosa and everything seemed fine for the first 3 months. Then new leaf off shoots from other stems started come in and the tips are brown. They also have seemed to stop growing? For example, in the attached image that growth has been in that exact state for a month. The one to the right has emerged more from the parent stem either. The leaves aren't unfurling, and it's pale and thin.
At the same time though, new shoots coming from the center of the plants are doing fine and the more mature leaves aren't showing any sign of distress.
Is it a humidity or a fertilizer issue? Since noticing the brown leaves, I've stopped fertilizing but it hasn't made a difference. Before I used very diluted liquid fertilizer (to avoid leaf burn) once a month as it was recommended during growing season. I also mist the leaves every other day, never during strong sun, to raise the humidity around the plant but to again avoid leaf burn.
Also, the aerial roots are almost non-existent. Do these come later as the plant matures? There are a few scraggly ones hidden there. Thank you!