Q.Why Doesnt My Staghorn Fern Grow Any Shield Fronds
It is growing in a pot and looks very healthy, producing new fronds

Certified GKH Gardening Expert
The shield ferns protect the root ball as well as collect moisture and nutrients. What kind of soil is in the container? If it's regular potting soil, changing to a lighter mix might help. Some use spaghnum moss or orchid mix. And if your fern is less than a year old you may need to wait a bit longer. Check your growing conditions against these and see if yours are ideal, i.e., light, moisture, humidity, fertility.
https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/staghorn-fern.html
https://mastergardener.extension.wisc.edu/article/staghorn-fern-platycerium-bifurcatum/
https://www.gardeningknowhow.com/ornamental/foliage/staghorn-fern/staghorn-fern-outdoor-care.htm