This isn’t a huge issue. I often play Minecraft with Shakespearian English on, and I have subtitles on. I’ve noticed that when I open or close a trapdoor, it says either “subtitles.block.trapdoor.open” or “subtitled.block.trapdoor.close”, instead of the actual subtitles.
This issue is being tracked at MC-296453. In the future, please use the MC project for Java Edition bugs.