order conformation page gives in the translations a 404 error and end point: order-paid gives the same 404 problem. When you save the permalinks it has been solved but the next day again the same problem. So some where it set back to the 404 error. Then again saving the permalinks solved it for only a day. I did some test and when the WPML string translation plugin is deactivated the error disapears
the problem of saving permalinks fix it only for a few hour in the night the error come back and the next morning you need to save again to fix the problem