Setting flash back to 30 seconds

I have a new xfinity box, the little one that connects to the modem with an internet cable instead of coax.  The steps to change the flash back or forward do not work to reset the time from 5 minutes ( exit exit exit 0030) .  All you get is LIVE and then a channel change screen to 0030.  I also tried xfin up up 2 to no avail.  Sure would be nice to have a manual or pdf document to show ALL  the options or better yet, a screen menu for settings.