Canon MF247dw User Manual page 594

Loading Paper(P. 45)
● Check whether mixed sizes and types of paper are loaded together.
Paper Jams Frequently with 2-Sided Printing (MF249dw / MF247dw)
Does paper jam frequently especially with lightweight paper or curled paper
during 2-sided printing?
● Set <Special Printing Mode I> to <On>.
Special Processing (P. 525)
Troubleshooting
586