So, you have faults that might have caused the failure to start, or might cause them in the future (plus the prospect of the engine cutting out when driving) but upon re-reading your first post, you say that both times it happened was after a short journey.
This can cause the engine to run rich at first and then if you stop the engine, it can get flooded with fuel, making it very hard to start some time later (even after several hours or overnight).
The key to knowing if this might be the case is whether the injector light stays on when trying to start: if there's a sensor fault (crank/rpm and/or cam/phase) then the light will come on and stay on and the engine won't start. But if it's only flooded, there will be no injector light.
See if you can reset the ECU to clear the faults and see if they re-appear when restarting, and if it fails to start, check for the injector light.
PS: The cure to start a flooded engine is to floor the accelerator (with ignition off) then keep your foot there and try to start: by opening the throttle you'll allow maximum air in and hopefully there'll be sufficient fuel still there to allow it to cough and splutter into life. You may however flatten the battery and set the alarm off in the process...
1996 Portofino 20vt & 2000 Pearl White Plus
1985½ & 2016 2017 Fiat 124 Spider + XF Sportbrake