As a Canadian I was disappointed to find my familiarities sided more on the US side than the UK. Now excuse me as I go look up 'gazump' ...
Then consider that that, percent wise, the number of English speaking Canadians in Hollywood are over represented wrt non California (again, English speaking) North Americans.
Then the family mixing between Canadians and Americans is huge. Most famously the families of the draft dodgers, but Im always surprised by the number of Americans who tell me they had a Canadian grandparent.
Finally, like my uncle (who also lived in and travelled extensively in the USA and CND) told me when I first arrived to the US from Canada: there’s a larger difference crossing North America East-West than there is North-South. Look at MN. They sound like they’re from Thunder Bay.
In short; Canadians help make US media, Canadians consume US media, Canadians are intermarried w/ Americans and demographically its as hard to distinguish an urban Canadian (Vancouver, GTA) from an urban American (Seattle, Jersey) as it is to distinguish a flyover Canadian from a flyover American.
https://www.etymonline.com/word/kerb#etymonline_v_1818
Basically, curb was a type of restraint meant to hold back. So a curb/kurb on the street is just a tiny retaining wall holding back dirt. Some times it is fun to look at etymology. Also makes phrases "like curb your ambition" make more sense.
Bill Bryson talks about this in one of his books (long time ago, I can't remember which) and it explains weird things like why the US pronounce Derby as it sounds but the Brits call it so it sounds like Darby.
"Mind you don't scrape your tyres on the kerb!"
They probably thought it was a trick question. Chucking in a word that sounds kind of like a real word, but spelled 'wrong'.
I guess you've seen it somewhere so your observation is equally as valid as mine, but I've lived (UK) in the North West, Midlands, and South West, and have worked in London, and I've never seen the word kebop anywhere ever.