Maintenance Loan for Mature Student

Hi there,
I submitted my application to SF yesterday for 2018/19. I will be 25 years old (almost 26yrs) when I start my course in September 2018 so considered a Mature Student.
The SF Calculator stated I should receive the full amount for Maintenance Loan which was £11,354. However on the application after I submitted it, it's saying it would be up to £5,700. I will be living on my own for the course of my university life and have not depended on my parents income since I was 18.
Currently I have an income of below £16,400 a year for part time work which may be £0 once I actually start university, depending on timetables etc. I did require SF help when I applied for a loan in 2013 but repaid what I owed as I left the course about 2 months in due to personal reasons, so unsure if this affects my amount?
I haven't been asked to provide evidence of household income, which I assume as I am over 25yrs would only be my own income and not my parents, which I'm happy to provide but was not asked during the application process?

Any information would be greatly appreciated!

Many thanks