I read through a couple of things on their website/zendesk support yesterday and it seems there is a way the chambers in the lock can get out of line, so with something thin you can realign them for the key to go all the way in. Without them aligned the chamber will only turn 90 degrees before stopping (which is exactly what I'm seeing). I had a go aligning mine yesterday with a cable tie but it was too wide and my eyesight is not good enough to see right into the bottom of the chamber. Am going to have another look today with a thin screwdriver (a thin piece of wire or spoke might also work well) and a light. Fingers crossed! Will report back!
Also submitted a support request with them. Expected 7-10 day wait time on response due to 'heavy volume'. GAH.
EDIT: also, welcome to Pedal Powered!
Haha Stockholm was similar when we visited 3 years ago. So. Many. Bikes!