If anyone has problems with “run on device of WFS” due to being unable to connect to wfs by wireless.
you can use this method to push your design to the watch for testing.
knowledge of ADB command line (DOS) is needed for this.
first in WFS click “publish” to publish/build your watch face into a apk.
Build and upload from Watch Face Studio | Samsung Developers
refer to
Preparing watch faces for publishing
then after you have publishing you do not need to upload unless you want to put to google play.
you need to just go to the build folder.
e.g C:\Users\myaccount\WatchFaceStudio\build\thisisatest
thisisatest = project folder.
then pair and connect with ADB
after connected successfully to your watch
run adb install nameofapk.apk