First, the way you built the net resulted in multiple overlapping polygons. I fixed this by turning on "delete geo but keep points" in the add SOP.
Next, I added more points by resampling.
Then I turned up the stiffness of your glue constraints... they were so floppy they looked like they were not working. I also increased bend and stretch stiffness.
Finally, I turned up the substeps in the vellum solver, otherwise you are going to get very stretchy.
You may want to look into the wire solver too for this kind of thing.
Then I turned up the stiffness of your glue constraints... they were so floppy they looked like they were not working.
Having a similar issue I just spent a lot of time searching my attributes for a mistake. Your answer just fixed my problem immediately. I never would have thought that the constraints were actually working but were too floppy to do anything.