Autavia chronograph not working correctly...

I bought my autavia a few months ago in February and love it.... but I just had to take it to my AD. The chronograph was not working correctly. When I would start the chrono the subdial minute register would tick over to show one minute had passed when the chrono seconds hand was only at about the 42 second mark on the main dial. Really strange. The watch is basically brand new so I must have gotten a bad one. The sales guy said he had never seen anything like that happen before. Anyone else ever heard of this? Im bummed...