macbook air connecting QNAP transmission issue

have 2 computers, both pc (win7) and macbook air (osx 10.11.2) connected to home wifi network.  win7 (using chrome) could connect to my Qnap NAS via following domain name, but my mba (using safari) could not, it just cannot load transmission main page at all until timeout. mba could only connect to transmission main page via ip address, not via domain name. any c-ching knows why?

double check both win7 n macbook ip configuration, specifically look for the DNS servers...

via HKEPC Reader for Android