PhD - Research Ireland / IRC Stipend help

Hi everyone, not sure if anyone will be able to help with this, but I haven't been able to get a clear answer on what seems like it should be a fairly straightforward issue.

I started my PhD at UCD in September 2022, funded by Research Ireland (formerly the Irish Research Council). However, although my Research Ireland funding started in September, UCD didn't allow me to formally register until October, and I didn't receive my first stipend payment until October.

UCD have now told me that my scholarship will end in August and that I should apply for a No Cost Extension so that they can facilitate my final payment. However, Research Ireland have told me that I need to apply for a retrospective deferral of my start date because of institutional delays.

What I don't understand is: if Research Ireland requires the PhD funding to start in September, but UCD doesn't allow students to register until October, shouldn't there be an established process for dealing with this?

Surely this must be a fairly common situation, and I'd be surprised if students are simply expected to lose their final month's stipend unless they know to apply for an extension or deferral.

The deadline to apply for the retrospective deferral is tomorrow, so I'm trying to figure out what I should be doing before then.

Has anyone else been in this situation with a Research Ireland/IRC-funded PhD at UCD? If so, I'd really appreciate hearing what you did and whether you were able to get the final payment.