I’m currently on stateside of the USA. If I want to start an activity, my vivoactive 4 doesn’t work. Tried to make a software update, but the watch don’t find the hote wlan network. What can I do?

"If I want to start an activity, my vivoactive 4 doesn’t work." - what exactly does it mean? Is it crashing, do you get an error, cannot sync, screen blank, no GPS position, or what? Hard to advise something, without knowing the exact symptoms.

If you want to update the ephemeris data, or the firmware, and cannot connect to a wifi router, use either phone's connection, or update the watch over the USB cable from a computer with Garmin Express.