The Open Browser special character seems to not work for everyone (small sample size of three...linux and two windows 10 pro users).
@umbral sierra and @wanton badge can provide more of a technical response, as they are more fluent with that language than I.
Basically, when I remap the Open Browser key onto my board and save it, the key only opens a browser when I already have a browser open. When I close all browsers, the key does not function.
Thanks.