Seems like the dimensions (e.g. 5mx2mx2m) that are displayed on the website are calculated after the upload is already done, that means that the dimensions displayed are actually the ones of the previous craft I have loaded.
As it is rather inconvinient to explain with a single craft, I have made a forum post displaying all three crafts affected by this bug:
LINK
EDIT: I had no idea that creating a bug report would result in this post being created, so I apologize for splitting it into two