Bathroom exhaust fan issue after new switch install
A photo of the wiring would help , but it sounds like you have 2 wires going to the fan and light and 1 hot and got them mixed up. Mark all 3 wires going to the switch 1,2,3 or a b c. Basically you need to swap the 1 wire that is all alone with one of the 2 on the other side. Now it will work or the light will be on all the time , if the light is on all the time the 1 wire on the 1 side of the switch needs to be swapped with the wire that has been on the other side all the time.