I don’t think it is yet, it’s acting the same.
However, I have a clue to lead you to where part of it(the weird gravity) is having trouble. It doesn’t like being offset in the Z axis. If you put the top of a cube at Z = 0 and add webs there, everything is fine but if you try messing with webs at the top of a default cube, it tries to stretch. The farther from Z, the more it stretches. I’m guessing you’re missing an offset somewhere in your algorithm. Putting it below Z really shows off the issue.
Even knowing this, I still haven’t got that traditional looking web shape yet either. This looks absolutely great for the kinds of webs spiders use in corners and when jumping though!