Make sure your ethernet is unplugged and your computer is connected by Wifi.
Double check your IP address is correct, in the Phone Settings, connections and debugging is on.
Enter your IP address manually in GWS using the + icon. For some reason they have GWS to start scanning at 10.63.* not 10.0.* so GWS doesn’t find the lower numbered IP addresses.
Assuming you already did that and it still didn’t find it, The problem may be you didn’t accept the RSA Encryption Key, if you don’t accepted it in a few seconds it will assume it is a hack and not show again. But usually this only happens when installing not for generating a distributor certificate.
In the C:\users\USERNAME\ folder is a hidden folder .tizen
rename or move the sdb and sdb.pub from that folder
restart your computer
restart your watch
wait one full minute after the watch and computer both are running
Make sure Debugging is turned on.
put your watch and a preinstalled watch face
An RSA Encryption Key acceptance should pop up a few seconds after you initiate the search and it needs to be accepted in 15 seconds max.
Samsung Developer Relations