#2419897: Javascript translations are loaded in the wrong order due to missing dependencies → changed locale module from always adding translations to only adding them when a placeholder file from a library is present.
On AJAX requests, the placeholder library has already been loaded by the main page, and therefore the logic doesn't kick in, meaning translations won't be parsed for any js files added by the AJAX request.
Since that issue landed, ckeditor5 copied the same technique, and has the same problem. 🐛 CKEditor 5 loads all plugin translations on AJAX operations Active is open for ckeditor5, but I could find an issue for locale anywhere.
Either replace the placeholder logic entirely, or add a code path that handles AJAX requests.
Active
11.0 🔥
locale.module