If both turn signals come on whey you apply the left turn signal, you have a mistake in the wiring. If your car is under warranty, you need to take it back to the dealer to get it fixed. It is a relatively simple fix.
There is essentially no restriction on using brake lights and turn signals at the same time, as they both signal actions/intentions that are often used in conjunction with one another. The brake light signals that you are using your brakes and slowing down, and the turn signal shows your intention to turn. As you will usually slow down as you come up to a turn, there will be many situations where both signals will be on at the same time.
Probably the Electronic Flasher. These ,when the fail,will allow the Signals and/or hazard lights to work intermittently. The flasher is the same for both the signals and hazards.
Try replacing turn signal flasher
threshold
threshold
If the lights come on but do not flash then the turn signal flasher relay is defective.
neurotransmitter
Turn signals and hazards are two separate curuits. Check/replace your signal light fuse and flasher.
The cornering lights are tied in with the turn signals - they'll come on automatically IF the turn signal is used.
as signals come in a means of extracting the original signal is required from the carrier frequency that process is called demodulation or modulation detection you called
You probably have a bad turn signal flasher (or relay, as it's called in some cars)
If the turn signal lights come on but will not flash you have a defective flasher relay. Replace the relay.