What could be wrong with my car?

I have a 2016 Chevy Cruze. For awhile now,
sometimes when I come to a stop and the auto stop
feature is enabled, it would not fully turn back on, but
the car didn’t shut off. I press the gas pedal and
nothing, but all my lights are on and music still plays,
it just isn’t running. To disable the auto stop feature, I
read on here to drive in L+6 so I have been. Recently
the car is now doing that even when I start my car for
the first time. No clicking noises. It turns on, but the
engine does not fully come on and vehicle will not
move. I have to turn it off and back on multiple times
to get it to fully turn on. When the vehicle is sitting,
the car sounds like it’s breathing and is not a
consistent run. What issues could these be?