Problem: You have garments where the seams display incorrectly when rendered - perhaps as transparent when they shouldn’t be, or the other way around.
Solution: Ensure that 3D Thickness (Legacy) value is set to 0 on the affected seams.
On the Resources tabs, click the Materials tab.
If not already open, click the Garment tab.
In Seams, click the appropriate seam.
Go to the Context view.
In the Workmanship section, under Thread Properties, ensure 3D Thickness (Legacy) is set to 0.