Thank you for replying - nice to see that the forum is back online. I still haven't received a reply to my emails, but no matter - the important things is that we've made contact
I've tried applying pressure in various ways and with varying force. At first it did feel like a loose connection but I could never find a reliable charging position and pretty soon the connection failed constantly, so now the watch is totally discharged and neither power outlet nor USB charging can get through to it no matter how I apply pressure.
I really hope that we can get the watch up and running before week 27 as I would be very sad if I have to do without it during my summer break.