Working Holiday Visa is Insufficient?

Hi,

I am applying for student finance and have been abroad periodically. I submitted my evidence in late June and it was assessed yesterday.

In the past year I have been in Japan on a Working Holiday Visa that shows my date of entry as November 08th and the maximum duration of stay for 1 year. However, today I was told that they needed more evidence to show that my stay in Japan is temporary.

I am confused as the Working Holiday visa is a visa that only permits stays of 1 year from the date of entry, so I didn't understand why it did not qualify me as a temporary visitor in Japan.

I do not have employment contracts in Japan that states these dates. However I can send an itinerary of my flight ticket to show that I will be return to the UK before 1st September.

Can I please understand why the temporary visa was not accepted by SFE processors? Will the flight ticket receipt be sufficient to prove that I am returning?