TheIritableOne

Sorry I might not have been too clear, within PaperCut you can run scripts against the print queues, that is what I'm referring to. I ask as the two browsers you've mentioned are both powered by Chrome and it's known for not adding an extension to the file name when printed. So it could be a print script or a filter/restriction set against the queue maybe?

Are you running a print script on the queue users are printing to, if so what is that script doing? Does the issue happen with all browsers?