Long discussion about the game: fine, acceptable, fun!

Long discussion about the meaning of a French word from hundreds of years ago after your bard said the wrong thing in a talking puzzle: might be fun, but is unrelated to the actual game and should be cut short before it drags on

The DMs job is to control the narrative, if you're talking about the game at all then it's part of the narrative and you should really only push them if they start going in circles or something at that point