It has to do with $terminfo not being consistent across platforms, the commit has been reverted see https://github.com/robbyrussell/oh-my-zsh/issues/2608 for details. If you got the hub tool installed the quick fix is:
cd ~/.oh-my-zsh
hub checkout https://github.com/robbyrussell/oh-my-zsh/pull/2625 terminfo_fix
and reload your shell. Without hub you need to setup the remote for the PR first and pull from there.