This seems a bit like you have used a clothing item, that does distortion to the penis.
As you may know, clothes are wrapped to th figures and vertices on the clothes are connected to nearby vertices of the body. It is like they were "glued to the skin" in some points. If you morph the clothes by mobing the body, this may cause some issues like those you have posted.
Please try the same scene with and without clothes.
If this is not helping with the issue, it might be some other form of distortion, like collision with invisible colliders, or bad morphs, or something completely else... It is very strange that this is only while using multiple figures.....
What you need to know is, that the male figure and especially the genitals, never have got the same amount of love like female figures. Making the females work was always the first priority. For instance clothing colliders or male to male penetration. There are multiple issues with the male figures and there is unfortunately nothing you can simply do about that.