The Swan Princess is an 8-part film series. Netflix only has three films: the 1st, 3rd and 6th:

The 2nd film from 1997 and 3rd/4th films from 2012/2014 are glaring gaps in the proper order.

The absence of the 7th/8th films from 2017/2018 is tolerable since getting licenses for new releases is harder.