I just discovered stag horn ferns and love them. I have two.
One is in a wire basket and a coco mat with moss. I had it in direct sun and moved it b/c some leaves were browning. I worry about water. I had it inside at one point. The leaves are limp but scared to water it more. The other is larger in an orchid box. The leaves are somewhat limp and a bit swiveled. I mist a lot. Trying to let both dry out and thought they would be happier outside.
First set of photos: about 1 month ago
Second set: as they appear now.

Thank you for your help!

I have never owned a Staghorn Fern, but when I walk in the mornings here in Florida I see several hanging in trees in front of peoples homes. They look healthy and happy. I think they need shade, but will live outside in summer in your area. The ones I see are in hanging wire baskets with coir mats. I would give them a good water if you put them outside, then the rain should be enough after that.

slowcala. I think leaving them alone for awhile and out of the sun, they will recover.

I have a few very large Common Staghorn Fern (Platycerium bifurcatum) in my yard; they are definitely shade only plants, enjoying bright light but no direct sun, which will dry them out and fry the fronds. A few in my yard are attached to and growing on the trees while another one is growing on a large chicken wire platform with a wood frame that hangs in one of the oak trees. I thoroughly soak all of them once a week with the garden hose. They are high humidity plants so they love the Florida climate.

If you are keeping your plants indoors, I'd advise watering them thoroughly by dunking them in the kitchen sink and then shake off all excess water before placing them back in a brightly lit location.

In your second set of photos, the plant on the right appears extremely dry and the sphagnum moss appears dry and compacted. Hopefully you will be able to re-hydrate that moss by soaking the plant for awhile.

plantladylin. We had rain since this morning so I placed both in a good spot for the rain all day. I just thought the yellow meant too much water.