Did you use an incandescent test light on the cam wires? Using a digital meter can lead to picking up stray voltage leading to a miss diagnosis. If you only have a digital meter, leave the plug installed and probe the wires from the back. On some plugs you can pull it back a bit to gain access to pins bit I don't know what type of connector you have.

The cam magnet has 3 bolts holding it on then a stem comes from the cam sprocket., this stem opens / closes an oil passage to actuate the advance.

With the cam magnet wire unplugged, I'd apply 12 V and see if the idle speed changes, if so this end of things is working. You might trip a trouble code when doing this.

Past that I'd need to see a wiring diagram.