Router losing connection with one wifi device

I was told to update the settings on my router to solve the connection issue with my Lyric Thermostat. I tried to log into my Netgear 78 router via the IP Address. I put the IP address into Safari on my Mac Book Pro and got a message that safari can't connect to the server. All my devices and internet are working, the problem is just my wifi thermostat.

This happened before when I was sent a message from Netgear to update my firmware but again, never could log into my router to do that. Can anyone advise me how to fix this issue?