Certified GKH Gardening Expert
Ferns are relatively carefree, and there are only a handful of things that can cause this.
Temperature can cause this, though, you are well within most ferns native regions
Lack of humidity can be a cause. They prefer a humid environment. Dry air will dry out the plant.
Lack of water is a very common cause. If the soil is allowed to dry out completely, this will be an expected behavior.
The most likely cause, is too much light. They can't handle full sun, so if the plant is allowed to creep into it at all, this can cause the issue that you are seeing.
Usually,it is a combination of one or more causes. You can remove any dead growth, leaving living growth alone. Giving it proper care, balancing its needs, will ensure a healthy plant.
This article will help you with their care: https://www.gardeningknowhow.com/ornamental/foliage/ferns/brown-tips-on-garden-ferns.htm
