modify permalink

hello
i have installed a plugin called instagram importer which auto posts instagram posts to wordpress if they match a certain hashtag
https://dsgnwrks.pro/plugins/dsgnwrks-instagram-importer

now, everything works ok but i have an issue. the autopost will post the content with the title as
post title #hashtag

i modified the function called the_title() such as

// modified by maurizio
  $str = $title;
  if (strpos($str,'#') !== false) {
    $str = substr($str, 0, strpos($str, '#'));
  }
  $title = $before . $str . $after;
  // end modify

so now the title appears as
post title

the only thing is that the permalink is still such as
post-title-hashtag
while i would like it to be just
post-title

can anyone tell me how to do so? maybe in the .htaccess file?
thanks a lot!