I had the same issues with the missing information (height/weight etc) which had already been submitted. For some reason, entering the data on my iPad made the information stick...
As for the additional questions; from tedious trial and error, I found that it was the first question (why do you want to work etc...) that was causing the problem. Shortened it by a few sentences and it all went through ok. Still can't explain what the issue is/was.