What type of soil is the plant in? What type of moisture monitor do you use?

I feel like totally dry is too dry for most of the plants you seem to be having issues with.

Whats the humidity situation? Do you mist the plants ever?

When was the last type you saw the roots/repotted/ etc?

Emily, you must be doing a few things right to have them that big and green! But wilting leaves even though plants have been watered means they're not able to take up that water, so look to the soil and the roots.

Salt buildup in the soil from fertilisers and/or minerals in your water can prevent the roots from absorbing water by creating an osmotic pull in the other direction. Or your potting mix might be old and compacted (soil level looks pretty low in photos), your plants might be rootbound, maybe there could even be some root rot going on - all of which interferes with the roots absorbing water. Overwatering can do the same thing but that sounds less likely for you.

Of course fertilising contributes to how well a plant will do but only once the above factors are sorted, I doubt just giving your plants a bit of this or that will be the answer.

First step I would flush the pots out with plain water ie. water them thoroughly until it's draining through, wait 10-20 minutes and repeat. This will dissolve any salts back into solution and then rinse them out. Like re-setting.

Cassandra, I see a nice looking one of these in the background of another post of yours, whatever you're doing must be working too!