Device Unresponsive

When a device goes unresponsive within Hubitat (as in, I am completely unable to control it although Hubitat still sees the device and reports no problems), what are my options short of excluding it and adding it back to Hubitat or doing a Z-wave repair?

I have one switch in the Master Bathroom that I can no longer control with my Dashboard. None of the other 4 switches in the bathroom have any problem. I'm not sure what's wrong with that one switch - it still responding to manual control.

Cut power to the switch, and power it back on again (using either the air-gap switch or at the breaker).

In general, such events indicate issues with your z-wave mesh. I would focus on making the mesh more robust.