While Samsung recorded a 7 percent drop over last year's second quarter, Xiaomi managed to achieve a solid climb of over 67 percent in the European market. This allowed the Chinese OEM to come first with 12.7 million units shipped in Q2 2021, while Samsung only shipped 12 million handsets in the region.
https://www.notebookcheck.net/Xiaomi-steals-Samsung-s-crown-in-Europe.553143.0.html
Not surprising that xiaomi is no.1 in Europe, but vivo being no.1 in China (with no.2 being oppo) is very surprising. Perhaps past huawei buyers that buoyed them in the domestic market have more in common with ov buyers than xiaomi buyers.