When dragging symbol of Unknown gender from "Family members not in pedigree" over the symbol with defined gender, preserve the known gender.
For example:
open pedigree and create a simple family mother-father-child
click on
Add family member
button -> a symbol of an unknown gender will be created in the
"Family members not in pedigree"
section
drag the newly created patient over the father node
father node will lose its gender ( it should not)