2-sided printing can be tricky depending on the printer. And, that's what I think's going on here. The OP is talking about having problems with his printer.
You're close to the mark. My printer is fine. I was surprised to see there are many options to print and combinations thereof. Unless you're a pro getting it to print 2 pages per side of a 8 x 11 1/2 in the right order is surprisingly no small feat. Now that I know how, I was offering to save someone the trouble if they were having any problems printing the 'Advance'(sic) manual.
Unfortunately "what's going on here", as you said, is even Radio Reference has its trolls. Mr. Alcawitty has trolled me on another post also. With as many messages as he's posted, he knows better but I guess it makes him feel important and superior. It is best to ignore him as I have.
Thanks for trying to help.