I think, this problem looks only with ULS including non-english letters. And sometimes U can see it with usial URL.

I correct it:
file com_properties\helpers\link.php

add string
$l = urlencode($l);

aprox. str.95
$l.='&Itemid='.LinkHelper::getItemid($Pview);
%here%
$link = JRoute::_($l);

and put this function to the end of this file

function translit($text)
{
$trans = array(
"á" => "a", "č" => "c", "ď" => "d", "é" => "e", "ě" => "e", "í" => "i", "ň" => "n", "ó" => "o",
"ř" => "r", "š" => "s", "ť" => "t", "ú" => "u", "ů" => "u", "ý" => "y", "ž" => "z",
"Á" => "A", "Č" => "C", "É" => "E", "Ě" => "E", "Í" => "I", "ň" => "N",
"Ř" => "R", "Š" => "S", "Ú" => "U", "Ů" => "U", "Ý" => "Y", "Ž" => "Z",
" " => "-",
);
if(preg_match("/[а-яА-Я]/", $text))
{
return strtr($text, $trans);
}
else
{
return $text;
}
}

Admin, please put first msg to the topic:
"Search Engine Friendly URLs problem"

You must to use acesef