Just to test out the problem, can you set up a subdomain for your site, something like: ny.syklubben.no and test it there?
@mrTablet Thanks. Those results really focus the effort.
Regarding your last reply, with fairly through detail on the 400 Bad Request. From the hosting company support folks?
In line with their point #2: Could you expand and check the formObject in the JavaScript console?
This is looking like a flavor of what I’m experiencing. Where I would look is in the Name of the form elements. Looks like I’m missing one, and that may be the trigger.
It looks like I have to pay extra for a subdomain. 
Given the info above in Point 2. FormData object not populating:
I checked, and populated the Name, and this resolved the POST issue (for me).
Thus my experience, and your Point 2. are the same. Not sure when this omission should be caught and notified in Elements. I’ll write this up and sent to support.
I have filled in all the name fields.
The next step is to expand the formObject in the JavaScript console. This may shed some light on how the form object is constructed (named, structured, etc.)
Can you also confirm that the very detailed reply was from you email hosting company?
