We changed our PHP to 7.2 a week ago. There were no problems but suddenly after a week there was a problem. Users were redirected to the cart after pressing the "Confirm Order" button on Checkout page and the order was not submitted.
I fixed it by changing back to
There were no errors in the logfiles, the server error log had no info as well. I just noticed that the form key did not changed?
There werent any code changes too.
Did anyone encountered the same problem and has found a solution?