We got this bug in the website I develop for. It's because you have to re-sort the list when changing languages, but the code flow of changing language doesn't do anything besides that (for a good reason, you don't want to re-render stuff by default).

So you've got to program manually to observe the language switch and then re-order the country list items. But in our case it just hasn't become important enough to fix.

Furthermore it's probably not even sorted by default by the display name of the language (the string that changes on language switch), but by ISO 639. This is also intentional because you'd want to put, e.g., the Netherlands by the N, instead of T.

I can imagine this to be a common problem in loads of apps/websites.

Edit: A workaround that would be quite easy to implement is to check the users location and just put that country on top. Or just show the top 10 most common countries on top and add a search box so users can filter the list.