I recently changed the language settings on my Macbook to full French language for a couple months. During this time, while Firefox of course was not able to translate all English websites to French, it did seem to automatically switch to the French versions of some websites that offer such language options.

Today I switched back to English, but for some reason Firefox is still automatically selecting the French version of available websites (this very Mozilla's support site, for example). Is this something that can be corrected by resetting my Firefox settings, or could it be a deeper Mac issue? As far as I can tell my computer and network recognizes my current location as English-based. Thanks.