Discount not in database

Hi,
We’ve been using the bulk discount plug-in for a while now but only recently found an issue.
I seems that since we’ve upgraded to WP 4.4.1 the discount isn’t working anymore.
It all goes well until the customer checks out and his order is written to the database.
The client can see that he has a discount but in the email that he receives and in WC-orders the discount isn’t there and the normal price is given and used for payment.

I guess it has something to do with the discount not being used while writing to the DB but I’m not sure.

https://wordpress.org/plugins/woocommerce-bulk-discount/