We replaced the original skylight when it cracked with this one from Amazon. It is lower and made of more substantial polycarbonate material.
Our 2015 skylight cracked in the first year and I patched it a couple of times with clear Gorilla tape. No problem since installing this skylight which replaces both the inner and outer domes.
https://www.amazon.com/Specialty-Rec.../dp/B00BFU6QWK