404 with bulk optimize

I use version 1.8.4 (latest right now). When I click on the link “Bulk Optimize” on the settings page it goes to:

https://domain.com/wp-admin/network/upload.php?page=ewww-image-optimizer-bulk

(I have installed the plugin as network admin)

I get a 404 for that URL. It works, however, if I remove the “network/” part from the URL.

https://wordpress.org/plugins/ewww-image-optimizer/