I have not contacted Kodak directly yet. The main reason is simply the current Christmas rush in our lab, which leaves very little time for escalation work outside daily production.
In addition, my former three technical contacts at Kodak are all retired, so I would first need to establish new technical people there. I did describe the issue to Kodak Alaris via a sales representative who is responsible for our region, but unfortunately I never received a response.
Regarding the frame position: in our case the defect is not limited to an optional 37/38th frame. It regularly often appears already within the nominal exposure range, typically around frames 36A / 36B, sometimes even earlier depending on how far the film advances before full take-up tension occurs. That is why we consider it a real quality issue and not simply “extra frame behavior”.
What makes this particularly relevant for us is that the same pattern appears across different Kodak 35mm films (color and black-and-white), different cameras, and completely independent of the development method (hanger, roller transport, rotary, or hand processing). This strongly points away from processing or camera handling and toward a manufacturing or base-related issue, possibly linked to how the film is attached to or tensions against the core during final winding.
Once the workload normalizes, I do intend to pursue proper technical contact and share representative samples. At the moment, however, that has not yet been possible.