How do I prevent double-sided printing on my Mac?

Ok, to confirm if you are using AirPrint, go to  > System Settings > Printers & Scanners, click on your printer to see what you have listed under Kind. For example on my HP Printer it shows AirPrint there.

Assuming it is AirPrint, is this the Double Sided option you are referring to when you print a document?

If that is not the issue, then I would recommend to use this link to Reset The Printing System. This will remove all printers and reset the defaults. You will need to add the printer again and when you do that, make sure under Use that it is set to the AirPrint (sometimes says Bonjour) option. Your printer will need to be connected to the same Wifi network as your Mac, which I assume is the case with your current setup.

Reset the printing system on your Mac to solve a problem - Apple Support

In addition to making sure that Double-sided is turned off on the Mac's Print panel.

Go to the Printers on-screen display menu and

1) make sure that Double-sided is turned off.

2) check for a Firmware up to date.

https://en.canon-cna.com/support/consumer/products/printers/pixma/ts-series/pixma-ts5150.html?

I would suggest to continue with the Reset Print System option and add your printer again.

• What printer are you using?
• Are you using AirPrint or installed printer driver from the manufacturer?