Dendrocygna javanica??????

I saw this duck in the east coast of Taiwan, between egrets, herons and moorhens. I don't saw anything similar in the bird guides of Taiwan. Only Dendrocygna javanica, that it's accidental in Taiwan, is slightly similar. When I approached enough, the duck taked flight and the wings showed a very tiny white border in the secondaries.

Please help me with ID

Done