It sounds like you have two web fonts in your prototype--Open Sans and Open Sans Condensed--and you're finding that Open Sans Condensed Bold is falling back to Open Sans Bold. Is that correct?
As a first step, please go to "Publish > Generate HTML Files > Web Fonts" and make sure that you have two separate .css links with their proper font-weights, one for Open Sans Bold and another one for Open Sans Condensed Bold:
If that hasn't been set up yet, you can grab the .css links from Google Fonts, here:
Open Sans Condensed Bold
Open Sans Regular, Bold
Feel free to also take a look at my sample RP file so you can see the setup of my webfonts. Hopefully it helps!
Open Sans Fonts.rp (65.7 KB)