stop start

I have a diesel 1.5 kangoo a few months ago will driving on the motorway it cut out, I pulled onto hard shoulder turned the key engine started and away it went as though nothing had happened 10miles same thing cut out but this time i switch off & switched back on again dove as if nothing had happened it has done this repeatedly traveling miles without problem or it can cut out every few yrds
I visited 4 garages and all say the same, can't find anything wrong, bring it back when it happens again. But thats why its at the garaage in the first place.
Can anyone help with this problem please :crazy:














has

stop start