Dakota, that's what happened for some people, myself included, but that isn't the issue. The issue is that (funny enough, I had it again just 5 minutes ago), even without clicking such a link, sometimes AFTER switching your language back to English it suddenly flips back to, in my case Japanese. Out of nowhere, when having MP open in English and then clicking an English link to a product, it opens that product page but flips to Japanese. I checked the links of some before clicking and they were designated with the /eng-en part in the link. And yet, after clicking then, they opened in Japanese... 🙂
Guess it's time for me to learn Japanese now!