Before assigning groups to any pull:

After assigning group A to pull A:

After assigning group B to pull B:

After selecting pull A in the list:

Assigning groups to different pulls doesn't make sense, but i got confused because certain groups were not highlighted green, even though they were assigned to a pull (they were assigned to multiple pulls by accident).
If you then delete pull B from the list, pull B gets deleted and pull A gets cleared (reference to #3)

#17