There is a study that indicates that domestic ducks may have "originated from another wild duck population that is currently undefined or unsampled, rather than from present-day mallard and/or Chinese spot-billed ducks, as previously thought". But I haven't found anything yet on the origin of ducks themselves.
Guo, Xing, Xin-Xin He, Hong Chen, Zhi-Cheng Wang, Hui-Fang Li, Jiang-Xian Wang, Ming-Shan Wang, and Run-Shen Jiang. "Revisiting the evolutionary history of domestic and wild ducks based on genomic analyses." Zoological Research 42, no. 1 (2021): 43.