Exclude PayPal as Channel / Source

Unfortunately, PayPal is shown to me as a last click channel for some orders. Presumably because the user went back to the page and the order completion page was called up again. How can I prevent this?
I want all orders to be assigned to the correct channels.

Welcome to the community!
We have a custom solution for this. To exclude channels from appearing you will have to go to Administration, click on a site and add the URL of the channel to a list of your sites just as in the following example:

As soon as you add the paypal URL to the list of URL, paypal should be excluded from the list of your channels and the data for this channel should not be aggregated in your reports anymore.