Utterly confused as to why I can't get a maintenance loan. Can anyone help?

So I applied for Open University, doing a Diploma of Higher Education in History and I have decided to do 120 credits per year on this course. I know I had to apply for part-time funding as it is Open University.
I was awarded my tuition fee loan in full and this is fine. However I understood that I had to apply for DSA in regards to maintenance loan as advised in the application, with it A) being a distance course and B) I have anxiety issues and depression , hence one of the reasons I am studying from home.

However I did receive my entitlement letter and it said that I could not have a maintenance loan due to it being a "Level 5" course which is not mentioned at all in the guidelines. It said in the first place I had to apply for DSA in regards to a maintenance loan, which I have done and been awarded in terms of extra help (councillor kind of person), but It has not changed my maintenance loan.
Also I am currently on Universal Credit, which I am not entirely sure I can continue on during my study, given that I am doing 120 credits per year, also I live with my mother who is a pensioner and I do not rely on considering I am 41 years old and take care of myself.

Thoroughly confused by the whole thing and annoyed at the contradiction that seems to exist all over the guidelines.

Hopefully someone can garner some sense from this and advise me.

Thank you

Ok,

Now I am very angry. Nothing in the guidelines states anything about level's of courses. I have had my assessment for DSA already. Your entire guidelines for Student Finance are entirely contradictory and make no sense at all. I may have to seek advice from elsewhere in regards to Citizens advice and maybe even a solicitor.
I have had nothing but issues applying for University for years and yet again SFE and the UK government make it harder and harder for the working classes to attend University.
How is this social mobility?

Also as I have already stated I am doing 120 credits for each year so it doesn't make sense.

Ok,

Now I am very angry. Nothing in the guidelines states anything about level's of courses. I have had my assessment for DSA already. Your entire guidelines for Student Finance are entirely contradictory and make no sense at all. I may have to seek advice from elsewhere in regards to Citizens advice and maybe even a solicitor.
I have had nothing but issues applying for University for years and yet again SFE and the UK government make it harder and harder for the working classes to attend University.
How is this social mobility?

Also as I have already stated I am doing 120 credits for each year so it doesn't make sense.