I have had this printer/scanner - Canon ImageClass MF644Cdw - for over 6 months now - this has never happened.
Now, when I scan, it does a little 1 second pause in between pages and adds a blank page to the .pdf in between each scanned page - now, a 10 page scan becomes a 20 page .PDF and so on an so forth - I use this every day and I don't need to have every PDF basically double in size.
Any advice on how to fix this? please advise - thank you!