Are there machines on buses where you hold the card to a reader instead of getting it punched?
Navigo Easy cards (which electronically store "virtual" tickets) can be used on Paris city buses.
On board Paris buses & trams are purple or blue card readers which are used to validate all types of Navigo cards including Navigo Easy. Here's a photo on board a Paris city bus with a Navigo card reader (white top, purple bottom half, with whitish circle pattern) on the left and a paper ticket stamping/validation machine (grey rectangular box with green sticker on front) on the right. For Navigo Easy, hold your pass flat up against the purple reader on the left until you hear a "ding" to indicate a ticket has been successfully validated. If you hear a "buzz-buzz" a ticket was not validated properly and you should remove your card & try tapping again.