You may have to. One thing to check is if video being recorded on the Beta deck actually has that black bar in playback. It’s common for the deck and kona to be in sync but the monitor be out of sync.
That being said if you have the option of using reference there’s no harm in doing so. Basically you plug power into the Horita. Then plug the ref bnc form the Kona into one of the ports on the back of Horita. Then run another bnc from another port on the Horita to the Ref in port on the deck. Also be sure to set the kona card to use ref in in the control panel. Keep in mind that since the monitor won’t be plugged into that sync signal it may still drift when monitoring the deck.