I had the same problem with the Ruby when it was new. My fitter did recommend short rides on it until I got used to it.

I used it for a bike tour a couple of weeks later and had miserable days and good days. On the good days I was wearing my Shebeest century shorts which have padding on the sides of the chamois. The bad days I was wearing my Shebeest Triple S short which has a thin liner on the sides of the chamois. While the irritation has gone away I haven't worn the Triple S shorts since. When I buy new shorts I make sure the chamois is completely padded.