I don't know how to do it, but I think the unit may have a bad seal or whatever the water routing is called.. A "rebuild" replaces seals, and probably some other parts. While in there, a cleaning would be warranted.
With many units, changing seals can be a DIY thing if you like, and parts are readily available. I think the access to the Kinetico documentation and parts is more specialized. They would like to keep that proprietary.
A backwash cycle(s) is/are a portion of the regeneration process. In most softeners, the first part is the backwash, and there may be a second backwash. It is the brining where the brine gets sucked from the brine tank and flows through the resin. That gets followed by a couple of rinses. Maybe the rinsing is not right.