For two people I have absolutely no relation to or actually know in person, I'm obsessed with their car crash of a relationship
The short answer is yes, he was living in London when they met. She says they met summer 2018, he left late 2019/early 2020. She claims Brexit 'tore them apart' but that isn't quite the truth. He had the right to settled status in the UK even if he lost his job - he just chose to move abroad despite 'dating' her. She also claims there aren't any advertising jobs in France and she can't learn French, so can't be over there with him. That also isn't quite the truth. He just won't marry her, so she could be with him on a marriage visa, despite her indiscreetly begging for it whenever she can.
She's been claiming for years they have solid plans to move back in together. She bought a house in the UK a few years ago and in the run up to it, she spoke very much as if he'd be there with her. Her last Q&A is even titled 'moving in together' when, well, they aren't. She claims he wants to be moved in to her house within the year in that vlog (11 April) - he actually got promoted in Monaco a few months back and has visited her maybe twice, three times in those years. You should watch that Q&A though, she gushes about how their first date was at a Pizza Express because she had a buy one get one free coupon. She acts like he took her to the Ritz. It's hilarious and sums up her delusion.
And a bachelor in his early thirties, living in Monaco, who only sees his 'girlfriend' once every six weeks tops - and isn't interested in her - he's certainly sleeping with others. He's incredibly secretive, hates appearing on her vlogs, and there have been comments on her YouTube videos about him being found on Tinder (although quickly deleted).