Z wave entity lost

Hello,
Very new to HA. Have been reading the forums and blogs but haven’t found an answer for my issue.

I am running HA version 0.28.2 in a Raspberry Pi 3 and a Z-Stick Gen5. I have successfully added several devices such as switches and lighting controls. However, I noticed that one of my light switches is no longer appearing on my list of entities under dev-state. The group in which I had added this light switch appears as unknown, and the switch itself no longer appears in the list of entities.

I’ve tried re-pairing it with the z stick, but the stick doesn’t seem to recognize it as a new device. I also know that the switch works because when I physically toggle it it turns the light on and off. It is a GE in wall light switch model 12727.

Any suggestions on how I may be able to troubleshoot this would be much appreciated. Specially, how does one remove a device from the z stick? perhaps if I do that and then re add it, this may fix the issue.

Thank you.