Questions about birth citizenship

Hi all, I’ve recently had an unsuccessful British passport application and couldn’t figure out why, until my mother suggested I didn’t have a citizenship.
For reference, I was born in the UK (after 2006), but my parents at the time did not have a settled status at my birth and only got it afterwards. I have lived here my whole life, had an education, applied for university, etc. My mother only arrived in the UK in late 2004, as for my father I do not hold contact with him since the divorce and don’t know much about his immigration. We have all lived in the UK since my birth with settle status/indefinite leave to remain.
I haven’t seen anyone else with this kind of situation, but I’ve seen stuff about the ARD form, would I be eligible for this? And if so, how or which evidence would I be able to provide?