So I figured out why this was happening, I am adding it as an answer in case someone else runs into or notices this.
This was occurring for my co-worker. It turns out that when this was tested at home, our website was opened through the Google Search App, which apparently changes the user agent to the "GSA" string. When we were testing this from work we were using Safari, which returned the good old, expected user agent string.
Not sure why the Google Search App changes the user agent, but that's what is happening.