IOS WWW Crash (Multithreading WWW issue?)

Receiving significant amount of crashes from our users when WWW downloading. (It appears it may be running WWW on multiple threads in each case).

This is on iOS, multiple OS versions crashing. We are running Unity 5.6.1p1.

Crash logs attached.

3116684–235757–crash-1.txt (113 KB)
3116684–235758–crash-2.txt (103 KB)
3116684–235759–crash-3.txt (108 KB)

We did three things and we killed off these crashes in our app. I think the core one was rolling back to the WWW library instead of UnityWebRequest, once I did that we finally got them under control.