Although Qualcomm are the designers of the S4 chip, TSMC are the company that take control of the manufacturing process and it is here that the difficulties have arisen.
According to a recent report by tech site Semi Accurate, 100% of production was halted at the TSMC facility in mid-February due to make unnamed changes to the manufacturing process. Although a date has not been set for production to re-commence, sources have suggested that volumes should return to normal by the end of March.
As always with such speculation, it is impossible to definitively state that the problems at TSMC will impact on production of any of the devices mentioned. However, a three week delay in supply is expected to have ramifications somewhere along the line.