Spot colours plates in files submitted for printing as screen print separations are not being printed and/or are being amalgamated into CMYK plates.
Serendipity Megarip does not have in the capability to process spot colours except as a separated black plate when printing in Screen Print Mode. In order to utilise the spot separation function in screen print mode, jobs must be submitted in Separated Postscript format.
It is likely the file has been submitted in file format incompatible with the Megarip spot colour separation function, such as TIFF image or PDF.
Use desktop design software to convert the file to Separated Postscript format and re-submit the file to Megarip. All job plates, including spot colours will now print.