Thanks to Glenn Jackman for helpful comments above.
The problem was due to a difference between GNU Command Line tools and OSX Command Line Tools. To solve the problem, I followed the steps at this website: https://www.topbug.net/blog/2013/04/14/install-and-use-gnu-command-line-tools-in-mac-os-x/
Now I am running bash version 4.3.42(1) and the man pages are working as I had hoped.