More than a month ago, a report came out claiming that Samsung is in talks with BOE about the production of OLED panels for some of the Korean company's smartphones including the upcoming Galaxy S21 or S30 or whatever else it is named. However, according to the latest rumors in the field, BOE's OLEDs didn't pass Samsung's internal testing so they won't be used. Reportedly Samsung isn't happy with the quality and therefore will continue using its in-house OLEDs. In fact, BOE was looking for a way to get into Apple's supply chain but also failed the initial tests for the iPhone 12 screen...
Source: https://www.gsmarena.com/samsung_will_be_using_its_own_oleds_for_the_galaxy_s21_lineup_after_all-news-43685.php