Kitchen sink faucet is clogged or internal cartridge has failed on cold side
It being RV junk probably NOT serviceable like a residential faucet.
(Remove handle, then unscrew top and pull internal cartridge)
Probably doesn't even come apart.
You can disconnect hot/cold lines ...swap them and see if problem changes to HOT side.
Better yet.......replace that RV Junk with a quality residential faucet.
I do that with every RV.....kitchen and bathroom. Then IF a problem I can service/repair with parts from any hardware store.
As Barney Fife would say "Nip it, nip it, nip it in the bud!"