OK so - I know exactly what is going on now. Described behavior is intended. In case of original pages vBET encodes URLs to safe UTF-8 - otherwise you would see broken characters on your forum page. It is because when you show string in other encoding that is the page then it will be decoded in wrong way - so you see broken characters. That is why in vbenterprisetranslator_functions_bbcode.php we have this code:
Code:
if (!$_REQUEST['language'] && vB_Template_Runtime::fetchStyleVar('charset') != 'utf-8') {
$translated = vbet_encodeToSafeUTF8($translated);
}
If you comment it then you will see nice URL in browser on not translated page with special characters, but those special characters will be broken on forum page. The issue is that vBSEO do not allows to recognize which URL generation is for page and which for browser URL. So we are not able to encode to safe UTF-8 only for URLs to view and leave as it is for broswer. It is vBSEO API limitation and it have to stay this way. This is not a bug - this is indented feature which allows to have nice view with special characters on not translated limited by vBSEO API which makes requests for URL rendering.

At this moment issue closed. If you have some comments, ideas, questions - just feel free to write We can reopen it if some crucial information will appear. I also move it to troubleshooting section as it is not recognized as bug.