Agreed, the input current spec is confusing
The power is limited to 50W .
Therefore with 25V input the current will be limited to 2A .
The input current should be specified as 2A to 5A : 25V = 2A, 20V = 2.5A , 15V= 3.3A, 10V= 5A , 5V= 5A
The DC/DC converter regulates the input current .