hook_file_download triggered twice on Firefox

I’m using a clean slate Firefox Quantum 63 testing my Drupal 8 website. It is well working on Chrome and IE but Firefox fired twice on hook_file_download API (some nodes automatically created twice). Any idea why this happened?

my hook looks like this:

function hook_file_download($  uri) {     $  node = Node::create([         'type'    =>  'article',         ...     ]);     $  node->save(); }