It error in /manager/processors/save_content_processors.php.
// check if alias already exists. if yes then append $cnt to alias
$cnt = $modx->db->getValue("SELECT count(*) FROM " . $tblsc . " WHERE id<>'$id' AND alias='$alias'");
if ($cnt > 0)
$alias .= $cnt;
That takes place:
1. At creation of aliasa existence is checked up the same and their amount.
2. At finding - an amount adds to the name of aliasa and saves.
That for example name a "new 1" - alias of "novost-1" is created. Saved.
If to create another "new 1" - another alias of "novost-1" is created - a script sees that it is an evil and "1" adds - "novost-11".
But! If to create another "new 1" - alias of "novost-1" is created again - a script again sees that it is an evil and the amount of such aliasov considers again, but as the past found is already renamed, "1" is again added.