Steps to Reproduce
1)Create a new PCG Graph asset.
2)Add some input parameters to it.
3)Create a new Actor Blueprint.
4)Place an instance of the above Blueprint in the level.
5)Select the PCG component on that instance and try to override any parameter (this is not possible in engine versions 5.5 and 5.6).
6)Copy and paste the PCG component: the overridden parameters on the new component are reset to the default values from the PCG Graph asset.
or in repro project:
1)Open L_Test level
2)Select BP_TestActor in Outliner
3)Copy and paste PCG component in details panel
4)Component PCG1 now has all the parameters reset to default values