Is Reddit automatically machine translating posts into other languages?

I've noticed an uptick in replies on /r/Nintendo in French, German, Spanish and Portuguese.

These commenters seem to think that they're discussing directly with the post, and they don't seem to even notice that the original post is in English and OP is writing in English.

Here's a recent example in German with the user's history also showing that he comments in German exclusively, replying to English comments.

Here's one in Spanish showing the same thing.

It's been long removed, but one time I saw an OP ask a question in Italian and then a user replied to it in Spanish.

We've set up automations to notify users that it's English and we've also set up automoderator rules to filter non-English posts, but some of these are still getting through.

If Reddit is doing this, it's a problem. We need our users to understand that our subreddit is an English language subreddit.