Please if you find this in the forum, Control D or copy paste it in your notes. 
I use “.\adb” instead of just adb. You will know what to use in the error and just follow what is suggested. This is the way to easily connect the GW6 even the updated GW5 and GW4 with 1.3.13. Thanks to @isaacok0919 and good luck to those who have 3 physical devices. 
"Hi, this is Isaac.
This method uses the adb command and requires some DOS knowledge.
The command to use is:
1.adb pair 192.168.1.xxx:xxxxx (The last 5 digits are the pairing port number.)
2.adb connect 192.168.1.xxx:xxxxx (The port number is 5 digits, and it is a wireless debugging number.)
To execute this command, you need a program called platform-tools distributed by Google.
You can search for it, download it in advance, and unzip it.
After that, run the above two commands in the command prompt.
If you pair first, it continues until you cancel the pairing, so you only need to use the port access command for the second WFS connection.
- Activate developer mode on your watch.
- Enable adb debugging in watch developer mode.
- Activate wireless debugging in watch developer mode and connect to wifi. (You can see the ip and port number.)
- Press the + sign to register the device. (If you press it, the pairing number, IP, and 5 digits of the port number appear. Do not close the screen, but you must perform the pairing command on the computer while it is open.)
4-1. Right-click on the platform-tools folder that you downloaded and unzipped in advance and click Open in Terminal to open a command prompt.
- Enter the pairing command adb pair 192.168.1.xxx:xxxxx (This port number is the port number indicated in pairing.) and then insert the 6 digit pairing number."