It sounds like it's the material this time. The newer materials are not of the same quality as we've had in the past. I used to used just any old pins and still do most of the time. I have recently purchased the tiny applique pins. I also plan on getting some of the fine silk pins that are very fine and have sharp tips.
Have you tried to spray a bit of just water and then steam iron?
Keep us updated on any different attempts with this project.
Pam M