As is, once a post is solved it’s revealed in the name, but this means you can’t then try to guess already solved posts - only new ones. If we reveal the answer in a spoiler in the post body instead, the sub’s historical posts will remain playable for new players to practice.
The reason the title gets edited is the way Lemmy handles related posts. Everytime you post, the related post list grows so until that changes, we will have to edit the title. Solved tags do not solve the problem, that was already tried.