Mass production of the iPhone Ultra has been underway for at least some weeks, but quality control inspections are reportedly rejecting all but a few.
The expected iPhone Ultra is still believed to be announced at the September 9 event, but supplies may be extremely constrained.
Reports have varied for months over whether the iPhone Ultra is delayed because of manufacturing problems, or whether those have been resolved. Now according to Nikkei Asia, however, production has been very slow.
Reportedly, Apple introduced a further inspection and verification process for the device during August. An unspecified source said that the additional process is concerned with production quality rather than there being manufacturing problems.