My similar issue in the past turned out to be ground wiring fault generating over current to the ECU along the time, then shutting down the bike at will. Nearly killed me twice, stopped several times. Struggled for 6 months, replacing kill switch, dismantling the entire fucking thing after a trapped wire until a friend suggested this ground wiring fault. Resolved replacing the coils and tested for a couple of months ok, then sold the bloody thing! Worse case of non corresponded love I ever had. Check my video on A-27 at night! Ah! slightly different of your issue, the bloody thing was resetting itself.
My GT1000 stopped recently. Same symptoms, engine not turning over. Battery was flat. RAC man charged up battery, managed to start the bike and checked with volt meter to see if battery was taking charge. It wasn’t. It turned out to be faulty regulator.