Why is Fuying Island dialect the same as Fuzhou dialect?

Fuying Island belongs to Xiapu area in Ningde, Fujian, and its dialect is actually more similar to Ningde dialect. Xiapu dialect and Ningde dialect are both branches of Fuzhou dialect, which were introduced from the Central Plains in the late Western Jin Dynasty and the late Tang Dynasty.

But Xiapu Fuying Island dialect is different from Fuzhou dialect. Give two examples:

Same: at night-touch (Xiapu dialect, Fuzhou dialect); Xiapu-Hubble (Xiapu dialect, Fuzhou dialect)

Different: children-rhinoceros (Xiapu dialect, Ningde dialect), second brother, Lieyang (Fuzhou dialect)