I found a bug that happens with the Menu Choices when translating to another Language. Randomly, some are shown as translated while others revert to the original English version. Without the Plugin in the project, the bug doesn't happen.
Thank you for reporting this, and sorry again for the late reply! I am unfortunately unable to fix this myself, but I filed a general report about config.say_menu_text_filter in the Ren'Py Github in order to hopefully find a solution. I will keep you posted!