Thorne is now played by Ingo Rademacher

https://www.fame10.com/entertainment/the-bold-and-the-beautifuls-5-worst-recasting-decisions/

In 2017, B&B announced it was replacing Windsor Harmon, who had been playing the role of Thorne Forrester since 1996, with actor Ingo Rademacher. This caused a huge backlash from fans. They were not impressed B&B was swapping out an actor who had played the role for 20 years, with a version of Thorne who seemed to fit Dollar Bill Spencer’s nickname for him, Ridge’s “milquetoast mayonnaise brother.” Fans were even less impressed when reports surfaced this year that Jacob Young (who played Rick Forrester) was let go to accommodate a salary for Rademacher. Viewers are still underwhelmed with the character these days, as he plays Katie Logan (who recently married Thorne after a five-minute courtship) like a fiddle. It remains to be seen if Rademacher will ever grow on viewers.