Always check your paper type with auto duplex printers.
Today I spent half of hour, many sheets of paper and a lot of inks while printing small book. And only because of wrong paper type in printer settings. I forgot that last time I printed on photo paper. My printer can’t do duplex on the photo paper and today it printed booklet pages in single sided mode.
Reverting back to plain paper solved that problem. It was really hard to understand, why duplex does not work. What’s a shame.