Aside: if it has caused problems for a while in your production - please
report!
Contacting via forum is okay, but taking the time to make a reproducible
bug report in the issue tracker helps a lot. I really could not do anything
without the stack trace, and the steps to reproduce the problem.
Keep in mind that developers get to work on the code base, but do not get
to use GeoServer. We really depend on issues being reported, in some cases
issues are well know, or have workarounds, but are not reported 
Thanks for including docker and curl examples today.
Jody Garnett