Maybe ask the employee if they are having personal life issues or have issues with the vision? I know I’m under a lot of stress lately and been performing slower than usual. Maybe you should consider if they are burnt out after being the first employee? Maybe they put in a ton of effort at the front end and now they need you to be a leader and help them become less burnt out.

You’re treating it like they’re a machine who is starting to break down and needs to be replaced. This is a shameful post for a founder.