There is a YouTube video that helps that exact situation I think the dropping one is getting too much water You should probably separate them though so you can care for them separately (don't be scared to cut them apart at the roots they'll be fine

In order for your plant's roots to function efficiently, there should be plenty of air in the root zone, from the top of the soil column to the bottom. If you're using a soil based on fine particles (like peat, coir, compost, topsoil, ......) and you over-water, soil in the lower 1/4 - 3/4 of the soil mass can become saturated and remain that way for extended periods. This is because water and nutrient uptake isn't a passive process, it's energy-drive, and that energy has to be produced by 'burning' food the plant makes in the presence of oxygen. Too much water in the soil = not enough air for roots to function normally = a drought response = wilting. Your plant can suffer severe dehydration even while it's roots are swimming in a sea of plenty. Get the watering under control. Don't water until a skewer or wood dowel (better) stuck deep into the soil comes out dry - as in the first day it comes out dry. Another possibility is a high level of salts in the soil contributing to the plant's inability to efficiently move water to it's distal parts - left tips and margins. If you've fertilized since you got the plant, you might need to flush the soil thoroughly, which is like hitting the fertilizer 'reset button'. Here's a tip: After you water Water at the sink and use enough water so the soil is saturated and at least 20% of the volume of water you applied exits the drain hole(s). This flushes accumulating salts from tap water and fertilizer solutions from the soil. After the pot stiops draining into the sink, hold it over the sink and move it up and down. You'll see Newton's First Law of Motion at work on the reversal in directions from downward to upward as water continues to move downward as you reverse the pot's direction to upward. When your pots are small enough to water at the sink and use this trick, you can remove ALL excess water from the soil in your smaller pots. There are also other 'tricks' you can use on larger pots to get rid of unwanted water that limits root function if you're interested. Al

Personally, I'd use a soil drench made with 1.47% Imidacloprid at the rate of 1 tsp/ quart (or liter) of water. It should provide immediate 100% knockdown, and will persist in the soil for quite a while. It works systemically in the plant, so should keep your plant free of predators like scale, mealybug, thrips, …………… . If you are unable to maintain your plants' root systems in a state of high vitality (good health), a healthy plant is only something you can wish for. To a large degree, your ability to provide a healthy environment for roots depends on your choice of soil; not to mention that an appropriate soil, one that allows you to water correctly w/o the plant having to pay the price exacted by a soil that remains soggy for extended periods, makes your job as a grower much easier across the board. If you like, I can provide a link to a thread that explains how water behaves in container soils. Gaining an understanding of the concept it outlines is almost certainly the largest step forward a container gardener can take at any one time. Al

Nothing in the picture is dying, Kerri, so don't worry about that. Have you changed anything? Position? Light? Water? Temperature? Have you repotted in those two years?