2010 570 Speedometer not working

Hi Guys

The speedometer on my '10 FS 570 has suddenly stopped working.

I can still switch on the dash by pressing the button and it shows time, hours, etc, but it does not register any speed.
It keeps showing 0 km/h, whilst driving along and then switches itself off after a short while.
It also does not switch itself on when I roll the bike out of the garage as it used to.

I checked that the magnet is still on the brake disc.
I checked the wiring for any breaks and the connectors and they all look good.
I replaced the speedo battery.

I have a voltmeter but I am clueless on how to use it. Was hoping someone might be able to give me some 'for dummys' instructions on what to check next.

Would appreciate any help.

Cheers

Thanks guys for the suggestions.

The Supermoto does not have the small connector near the caliper. The cable exists the sensor and is in one piece right up to the connector behind the headlamp. There has not been any rain here so I do not think it is moisture related.

I was hoping someone could give me an idea how to narrow down the issue, eg. if I jack up the bike and spin the front wheel, what should I measure for?

Is it (change in) continuity?
Or voltage?
What values would one expect?

Thanks for any help.

Just a quick update:
I have swapped out the sensor + cable (Part no: 80014068100) and everything is fine with the world again

Cheers