Steps to reproduce the issue:
1. follow the tutorial from the lower link to retopologizing a low poly mesh and creating a high poly mesh.
Link: https://manual.reallusion.com/Character_Creator_3/ENU/3/Content/Character_Creator_3/3.3/09_Transformer/Importing-HD-DAZ-Characters.htm
2. then instead of baking them, reimport both mesh obj files into 3d program and check them.
3. keep active both objects into the viewport and see.
4. you will find that Character Creator changed the pose a bit.

Actual Result:
Pose changes when you retopologize using Character Creator 3.

Expected result:
It should be the same as before.