Tethering by hotspot via USB IOS9 and Itunes 12.3

Dear all,

I used to let my late 2009 Mac mini to gain access to the internet by personal hotspot of my Iphone 6 via USB and its works fine. The USB connection still works fine after my Iphone 6 upgraded to IOS 9 this morning when I connect it to my mac mini. However, after the itunes in mac mini upgraded to 12.3 just now the hotspot via USB does not work anymore. I tried reboot both device but in vain. In network preference of my mac mini it always shows the USB connect is not detected. I now have to use the hotspot via wifi and bluetooth and its way slower than USB. Any help from you is much appreciated. Thanks!

Regards,

Wilkie