Stachys Byzantina Silver Carpet - Cut back?

Should I be cutting this Stachys down to ground level?  I’m getting conflicting advice when I’ve checked online but some of the leaves are quite rotten and I can see new growth in the middle of the plant.  I planted it as a small plant in October 2020 so this is the first time I’ve had to deal with it after growth.  I’m thinking I probably should but want to check with ‘experts’ before I kill it!!