“It’s not just Love Island: “fake British accent” videos have over 188,000 views on TikTok, where young people say they use the voice whenever they feel uncomfortable.”

Maybe a way of unconsciously adopting a “Keep Calm and Carry On” perspective in unexpected circumstances?

https://getpocket.com/explore/item/why-are-so-many-young-americans-adopting-fake-british-accents