Unexpected results trimming with words()

I use _.words in a few places in my code to split natural English phrases on certain keywords. This works just as I expect most of the time. With one keyword (maybe more as I try more words?) the words in my result list sometimes get trimmed. The trimmed characters seem to have a connection to the characters in my delimiter string.

My delimiting string in this case is " with ". Here are some examples:

_.words("Window with Area > 100", " with ");
["Window", "Area > 100"]

_.words("Window", " with ");
["Windo"]

_.words("West with Area > 100", " with ");
["West", "Area > 100"]

_.words("West", " with ");
["Wes"]

Am I doing something wrong or is this intended somehow? Apologies if this has been reported. I search through the existing issues and didn't find anything relevant.