I use Google docs all the time. I print a lot of it out for church.
I create A5 PDF’s to print off as double-sided 8-page hand-outs.
When saving as a PDF to print off in booklet form, I was getting blank pages inserted. Super irritating.
The “fix” seems to be to click on Print, and in the print preview change “Margins” to “Customised” and then just move the left margin a tiny amount.
Bingo. From 16 pages with every other page a blank, down to the correct 8 pages ready to go.