Modern Vespa

Sometimes the roll lock button - to block or unblock the front wheels - becomes unresponsive. I got to push it again. What could it be? Thank you

Are you aware the tilt lock is only operative at speeds below 5km/h?

Above 5km/h the tilt lock is just along for the ride

yes, i am aware.
I am using it on stops.

Could be glitchy switch, wiring problem, old/weak battery, charging problem etc, etc, etc

Best to start by consulting the workshop manual

I read it is 10km/h

Tomato, tomatoe
The roll lock system is only available at very low speeds

Using the roll lock at every stop puts excessive wear and tear on the system

Putting your feet on the ground is the better and safer way

I ment long term stops, not at the semafor

What is a semafor???

The roll lock system is not designed for long term parking.

semafor is trafic light

do you really dont know what a semafor is? you need to go out more than and visit places

Why didn't you say traffic light to begin with?

The word "semaphore" has multiple meanings

https://en.wikipedia.org/wiki/Semaphore

The last time I saw a semafor on a vehicle was a turn signal indicator on VW Beetle from the 1950s