Unable to attribute an order to a sales channel

Hello, I am following instructions here to attribute an order to a specific sales channel. It used to work a few months ago but currently all orders are shown as from “online store”, even though I am appending the access_token url param to my cart and checkout urls. An example:

https://xxx_store.com/checkouts/c/259752a98343e440edaefbd05dcc43f9?_ga=2.257915467.1546776.1675780550-2009103388.1675d80550&access_token=xxxxxx

Does anyone know why it stopped working or am I doing anything wrong? Thanks in advance for your help!

@CB2023 Did you find the solution?