So, yes.

https://github.com/robbyrussell/oh-my-zsh/wiki/Plugins#githu...

oh-my-zsh is, imho, way overengineered and bloated. Leads to all sorts of issues like the one you're encountering there.

I would recommend sticking to a plain zshrc file that you can read, edit and fully understand.

The one I wrote and am using day to day is available here, with documentation: https://github.com/jleclanche/dotfiles