If this occurs (with ZZs) when you can still detect moisture deep in the pot with a "tell", you're very likely over-watering or one of the damping-off fungaluglies are at work rotting roots. If it doesn't regain turgidity and plump up within a day after-watering, serious damage to roots has likely occurred due to a prolonged period of dry soul and root desiccation. A high level of dissolved solids (salts) in the soil solution can also cause the symptoms shown. Using a 'tell' Over-watering saps vitality and is one of the most common plant assassins, so learning to avoid it is worth the small effort. Plants make and store their own energy source – photosynthate - (sugar/glucose). Functioning roots need energy to drive their metabolic processes, and in order to get it, they use oxygen to burn (oxidize) their food. From this, we can see that terrestrial plants need plenty of air (oxygen) in the soil to drive root function. Many off-the-shelf soils hold too much water and not enough air to support the kind of root health most growers would like to see; and, a healthy root system is a prerequisite to a healthy plant. Watering in small sips leads to avoid over-watering leads to a residual build-up of dissolved solids (salts) in the soil from tapwater and fertilizer solutions, which limits a plant's ability to absorb water – so watering in sips simply moves us to the other horn of a dilemma. It creates another problem that requires resolution. Better, would be to simply adopt a soil that drains well enough to allow watering to beyond the saturation point, so we're flushing the soil of accumulating dissolved solids whenever we water; this, w/o the plant being forced to pay a tax in the form of reduced vitality, due to prolong periods of soil saturation. Sometimes, though, that's not a course we can immediately steer, which makes controlling how often we water a very important factor. In many cases, we can judge whether or not a planting needs watering by hefting the pot. This is especially true if the pot is made from light material, like plastic, but doesn't work (as) well when the pot is made from heavier material, like clay, or when the size/weight of the pot precludes grabbing it with one hand to judge its weight and gauge the need for water. Fingers stuck an inch or two into the soil work ok for shallow pots, but not for deep pots. Deep pots might have 3 or more inches of soil that feels totally dry, while the lower several inches of the soil is 100% saturated. Obviously, the lack of oxygen in the root zone situation can wreak havoc with root health and cause the loss of a very notable measure of your plant's potential. Inexpensive watering meters don't even measure moisture levels, they measure electrical conductivity. Clean the tip and insert it into a cup of distilled water and witness the fact it reads 'DRY'. One of the most reliable methods of checking a planting's need for water is using a 'tell'. You can use a bamboo skewer in a pinch, but a wooden dowel rod of about 5/16” (75-85mm) would work better. They usually come 48” (120cm) long and can usually be cut in half and serve as a pair. Sharpen all 4 ends in a pencil sharpener and slightly blunt the tip so it's about the diameter of the head on a straight pin. Push the wooden tell deep into the soil. Don't worry, it won't harm the root system. If the plant is quite root-bound, you might need to try several places until you find one where you can push it all the way to the pot's bottom. Leave it a few seconds, then withdraw it and inspect the tip for moisture. For most plantings, withhold water until the tell comes out dry or nearly so. If you see signs of wilting, adjust the interval between waterings so drought stress isn't a recurring issue. Al

I don't think mushrooms are dangerous, but they indicate moisture that may be too much for the plant. Peat most likely keeps the mix too wet. I do not see reason for adding peat. Perlite helps drainage, but there should be more of it than what's visible in your photos. How do you know that soil is "pretty much dry"? It may look dry on surface, but could be still quite wet deeper.

looks fine to me.. let it near dry between waterings .... to avoid rotting the rots like they did at the store ... if it gets too dry.. it will wilt a bit.. but then you will now it needs water ... perhaps count the days.. so you can understand how long your mix takes to dry out ... i dont understand why you used a mix of part wet.. and part dry media... but it appears to have worked .. and i sure hope you used media.. and not garden soil ... ken

ZZs grow two types of stalks. The ones that are typically at least the width of a pencil and they come out of the soil with the leaves tightly bound around them. Then they also grow these very small stalks that typically only have about 3 leaves on them. This is completely normal. The small stalks don't live too long. It has been hypothesized that these small stalks are produced to provide energy to the rhizome so it can generate the larger normal stalks. I usually let the small ones live and die on their own. Once they turn brown and crispy, I will cut them off where the stalk looks dead so I'm not cutting into green flesh. I hope this helps!