It works fine for me even outside the home network. There can be delays if the bandwidth is low on a foreign WLAN. There are also problems with sound transmission (chopping and interruptions). But the pictures are transmitted. I can't find any setting option that could help with your problem.

The camera needs a Wi-Fi network to transfer the image to your app. When you use it on the road, you have to hold the reset button under the lens for 5 seconds and set up the camera as a new camera in the app, selecting the Wi-Fi network from your new location. Without Wi-Fi you won't get a picture. (You could theoretically buy a mobile Wi-Fi router if you want to take it everywhere).