Steps to reproduce:
- start a new CC3.4 project
- add CC3+_Neutral_M.ccAvatar to the scene to replace the default female
- add Hair Template -> Element -> Beard -> Beard & Brows Builder -> Chin Curtain -> Long Full to the scene
- rotate the character to look from the right and zoom in so that the beard is clearly visible
- notice that the beard has some kind of deeper lines as if there are sharp edges of some barely visible object intersecting with the skin. See the attached image1.jpg, where I have highlighted the edges with red underlines. At this point, these edges will be barely visible, but they'll cause issues later on, as explained in the next steps.
- in the Scene select "Chin Curtain_Long Full"
- open Modify tab and click Conform button
- imagine that you have edited the mesh and now want to recalculate collisions - click Calculate Collision button. Click it three times to simulate as if you have done multiple edits and recalculations.

Actual result:
the edges of the unknown object inside the beard become more and more visible on every use of Calculate Collision button, as seen in the attached image2.jpg.

Expected result:
there should not be such a hidden object inside beard. Calculate Collision button for beards should work the same way as for hair, that is - resulting in better conformity of strands with the skin without any artifacts caused by the unexpected objects within the beard mesh.

As a workaround, I did the following:
- in Scene tab, hide all Avatar items except "Chin Curtain_Long Full"
- in Modify tab, click Edit Mesh button
- at the bottom of the Modify tab set Render State to Smooth. Now the foreign object inside beard is clearly visible and has dark coloring; see image3.jpg
- click Face under Edit Mesh button
- select any face of that dark mesh
- at Selection Tool click "Grow selection" button many times to make sure the dark object has been entirely selected (about 10 times should be enough)
- at Visible Brush click "Hide" button
- at the bottom of the Modify tab set Render State to Normal.
- click Edit Mesh button to exit edit mode
- in Scene tab, unhide the Avatar items

After these actions, there were no more artifacts visible and I could edit the beard mesh and use Calculate Collision button as many times as required.

I'm not sure if the object inside the beard is supposed to be there, but it seems working much better without it.