submodule cloning issue

I am seeing a problem with cloning a repo with submodules while on my
company vpn. One of the submodule urls has an http redirect. It will
timeout trying to clone that redirected submodule and only that
submodule. I would say that it is solely an issue with my company vpn
however I can do a git clone of the repo that is failing and it does
properly redirect and clone. So there is a difference in how git
submodule--helper clone works vs git clone. If I drop off of the vpn
it works without any problem.

I am seeing the issue with version 2.25 and 2.26 running under ubuntu.

I have not had time to dig into it further to see what is going on.

Here is the repo that is having issues.

https://github.com/ycm-core/YouCompleteMe.git

This submodule that is buried in there is redirected to a new url. It
will hang trying to submodule clone.
https://github.com/mitsuhiko/flask-sphinx-themes.git