I’m receiving the incorrect amount of maintenance loan for student finance

So I just found out I’m getting £9,446 in maintenance loan, but my household income is under £25k, which should mean I qualify for the maximum maintenance loan. Naturally, I contacted Student Finance about it, and they were super unhelpful and kind of passive-aggressive. They told me they assess income from the 2023/24 tax year and get their info from HMRC, and basically just told me to contact HMRC myself.
The thing is, our income was under £25k for 2023/24, and for 2024/25 it's even lower (about 17% less), so I genuinely don’t understand how they’ve assessed our income as over £30k??
What’s even weirder is that both my siblings are getting different amounts. My twin, applying to the same uni at the same time, is getting around £8.5k. But my older sibling is getting the maximum maintenance loan. So now I’m wondering if Student Finance screwed up, or did HMRC?
Both my parents P60s clearly show that their combined income is way below £25k. I even offered to send in the documents, but the lady on the phone literally talked to me in a baby voice and said something like, “get your mum’s income, get your dad’s, add them up, what’s that number? Now contact HMRC” and then just hung up. Wtf? I was nothing but respectful while trying to explain.
I’ll be contacting HMRC, but I have no idea what to even say to them. Also, my parents don’t speak English very well, so their mainly relying on me to talk to them. I really need help ASAP.

Hi there,
Just to check, are you going into your final year in the 25/26?
Thanks, Graeme

Hi, no I'm starting my first year in 25/26 September. I really need help on what to do, should I get my household income reassessed for 24/25?

Thanks, there are two options here.
First of all, it's definitely worth speaking to HMRC - if the income they have for 23/24 is incorrect they can correct this and we'll then use these figures. So, once HMRC tell you they've done this let us know.
Second, do your parents expect their income to have dropped by more than 15% in the 25/26 year, compared to 23/24?
Thanks, Graeme

Hi, it turns out the employer got my parents income wrong when reporting back to HMRC so we're trying to sort this out. We've also figured that'd be shorter to fix this by reassessing our household income for the current year 25/26 because our income has dropped more than 15%. I've found the form online but my parent's don't know how to fill it out properly, so I'll be calling SFE to help walk us through filling out the form. Any advice?

Hi, I called and know how to assess my household income for this current year 25/26.
My parents income right now is definitely 15% lower than it was last year and they definitely won't be able to support me financially this academic year, however their income fluctuates. My parent's are worried that if they assess my income now as what they're getting currently this year, their income at the end of 25/26 (when their P60's come) will show that their income is higher than what they estimated it to be, leading to me being overpaid and I having to be pay it back. My mother, especially, doesn't have a full time income as she works part-time and isn't sure if she's going to be working less or more throughout the year since it varies throughout (25/26) meaning she's having a difficult time estimating what her income might be. What should we do? I did try contact SFE through the online chat but the person talking to me wasn't helping me at all and was telling me things that I already know, even though I stated my question clearly. If our income fluctuates throughout my academic year, could I let SFE know this so I don't accidentally get overpaid and charged? Thank you