I found out the problem. It’s a bug in the plugin.
In the plugin there is this line:
if ( ! in_array( ‘woocommerce/woocommerce.php’, apply_filters( ‘active_plugins’, get_option( ‘active_plugins’ ) ) ) ) { exit;
When woocommerce is multisite wide activated, this is saved in get_option(‘active_sitewide_plugins’) instead of get_option(‘active_plugins’) which will cause this if statement true and exit the script.
For more info check: https://wp-buddy.com/blog/check-wordpress-plugin-sitewide-active-network-active/
I have fix it for now on my wordpress install, but please fix this bug in your plugin.
Thank you.