Ensure the subtitle file name matches the "BluRay" source tag to avoid "drift" (where the text appears too early or late).
Use VLC, MPC-HC, or IINA, which handle HEVC and EAC3 effortlessly. subtitle Chinatown.1974.1080p.BluRay.HEVC.EAC3-...
Most Blu-ray releases run at 23.976 fps. Ensure your subtitle file is timed accordingly. Ensure the subtitle file name matches the "BluRay"