Wired floodlight cam disappeared off list.

I have a few floodlight cameras installed for the last 6-8 months. They were all on device list however one of them seems to have disappeared off the list?? It seems to have power as the lights are coming on at night. However I cannot see it on my device list. I tried to set it up as a new device but the light at the bottom isn’t flashing and I can’t get up to it to press the button at the top.