Printing Errors or Lights & Stuck Print Jobs

I just upgraded to a new HP Envy 7155 All-In-One, from my old Envy 5660.
I was a little surprised to see that the new 7155 didn't have the same automatic tray feature as the old 5660, which would automatically extend the tray as soon as a print job began. Not a deal-breaker, just surprised.

But now I'm finding out that the 7155 doesn't seem to be able to AUTOMATICALLY print double-sided documents.
On my old 5660, the first page would print, then the printer would pull the page back in and print the other side with no further action required by me.
But on this new 7155, it seems the only way I can print a double-sided document is to print page 1, then MANUALLY reinsert the page back into the paper tray.

I went through the initial "test" procedure the first time I tried to use double-sided printing, and everything turned out exactly as expected, but now I get this pop-up dialog every time telling me to manually reinsert the page.
Can this be right? What am I missing?
Is this Envy 7155 not capable of automatic double-sided printing??

If this is be design, then it would be a major step backwards for me, and the printer may have to go back...