In search of Movie

The story follows a young boy who discovers an old fireplace in his home, which becomes a portal that sends him back in time to World War I. There, he meets the people who once lived in his house, including a little girl. The boy later meets this girl again as an elderly woman in a nursing home, closing the loop on their connection across time. I think the movie plays off in old UK . The boy has short dark hair. He is also bullied in school which leads to him hiding in the fireplace and discovering the time portal. The movie is between 1990-2000