Unfortunately, nothing has reallyl changed from when this request was originally put in here. We cannot assist further as we cannot go through the relevant steps to identify the issue.
While I fully understand this may be frustrating, and you may feel the issue is no 3rd party, I would ask you to consider the fact that there are no logs related to these, no failed transactions related to these and its only happening on your site. So there is indeed something specific related to your setup that is causing the problem there.
Without being able to progress through our diagnostic procedure, we are unfortunately at a bit of a stalemate. You had a ticket there, which would have been escalated with details at the time, however without 3rd party items being allowed by yourself to be disabled, we would not be able to assist.
You did also state you found the issue and it was a bug, but provided no information for this