I've heard people talk of NI seeming to underperform - if so that likely boils down to Irish Nationalists due to them fundamentally believing the UK has no will or desire to represent them since from their perspective the Tories are effectively in government with anti-peace loyalist terrorists.

Combine that with what I assume is a gut instinct on an identity level to "never ask the Brits for anything" and a sense that the petition won't do anything, and you have a perfect storm of disenfranchisement.

(I have observed a growing sentiment in the Republic that ironically they would probably be better off under Direct Rule until Reunification after the Brits next general election, in part because the Brits will need to be on their best behaviour towards Irish Nationalists as any trade deal with Europe will require shows of good faith from the UK towards Europeans under their jurisdiction.)