Duplicate tracking of ecommerce orders

We have issues, that several Orders are tracked twice. It happens, when users are visiting the checkout success page again. We are using an unique orderId. You documentation is saing, that the old order will be dropped, when its tracked again: https://matomo.org/docs/ecommerce-analytics/#tracking-ecommerce-orders-items-purchased-required

Could it be possible, that this is not working, when we have enabled DSVGO/GDPR related options like anonymizing orders number?

Case:

Matomo-Version: 3.8.1
MySQL-Version: 5.5.60-MariaDB
PHP-Version: 7.1.26

Hi, no answer for this ?

Hi @DIGITAL_ACTSTAR, @toitoit
I don’t find this information anymore.
The only thing I found is:

Note: The unique order ID generated by your cart software ensures the same order isn’t tracked twice

This could be interpreted as this is unique from point of view of cart software and/or from the point of view of Matomo tracking…

Which Matomo version do you use?

@innocraft, how Matomo should work for order ids?
I saw this:

fyi: When tracking an order that has the same OrderID Matomo gives the following error:
Invalid non-unique idsite/idorder combination (1, 000143), conversion was not inserted.