2012 Ford Kuga hesitation and stalling.

Morning. New member and really hoping for some advice.
I have 2012 kuga and recently getting worse on drives.
when I got car few months ago in 2nd there was sometimes a hesitation like a drag when putting foot down but lift clutch and go again and all fine. drive normally all day.
recently I can be cruising around 70 and I feel the car like hesitating like the timing very very slightly out then all of a suggest a jolt as if out of gear and if I catch in time and clutch down it stops and then I can carry on BUT if I don’t catch in time car will stall and engine malfunction light will come on. If I push start button car starts and drives perfectly normal again. Sometimes all day and sometimes for an hour before happens again.
it’s really strange and my mechanic changed the sensor on crankshaft and no change.
I can drive a whole day and nothing but then other times really bad hesitating all day.
also I have noticed after a long drive if I stop say at lights or a junction and start to pull off on 1st or 2nd it’s really juddery but again clutch control saves it.
Any thoughts. Mechanic says egr but why does it act perfectly if I restart car ?? Surely it’s a sensor that when I start it just resets. Could it be ecu issue. ??
also one more …….. when driving long journeys as I do on motorways every so often the drivers door opens by itself. No leaning on it it just opens and light comes on and warming sound. Again I close and may not happen for days or weeks.
Many thanks in advance.
gary