I've dealt with Charter and Cablecards with TIVOs.
I'm assuming the HomeRun should be similar.
You absolutely require a CableCard to decrypt content.
In many areas you also require a small box aka Tuning Adapter
aka SDV (Switched Digital Video) Adapter.
If you care here is a description of SDV
The FCC has a cablecard "Know your Rights" page -- »www.fcc.gov/guides/cablecard-kno···r-rights
Tell Charter you're filing an FCC complaint -- this will
get a bit of action... AND FILE THE COMPLAINT
(Category Broadcast (TV and Radio), Cable, and Satellite Issues)