I have a 2017 Hyundai Tucson and last year this problem only happened once, but now it has been going on for the past 3 consecutive days. If I have my headlights on or on auto and I use the left signal, the headlights turn off. Only the left, not the right. The display on my dash displays the lights going to off and back to auto or on when the signal has been activated and then stopped. Any ideas?

 

It could be ,
there may be a broken wire in the steering column up near the directional switch,
There is also the possibility of a problem in the wiring or system for the left turn signal light system.causing a circuit breaker to open when left turn is selected.

Last question, does the left turn signal light work as it should when selected? If so, it most likely would involve the first possibility.
Don't know at this point if there is a "Lighting module" involved..

 

Yes the signal works when selected.

 

One thing I noticed, is if I just slightly hold down the turn signal, for instance when you're switching lanes, it does not shut off the lights. It is only when the turn signal is pushed all the way.

 

I believe your vehicle has what we call a combination switch. From what you describe I would be inclined to believe that there is a problem within that switch. Replacement will probably be required.
That switch goes for around $75.00, might want to get a second opinion, never hurts.

 

Your profile doesn't show your location. Does your car have a parking light mode which requires the turn signal to be operated and the ignition key turned off to set the parking lights?

 

Multi-function stalk switch

 

Only the left turn signal turns make the headlights and interior lights blink out momentarily. Looking for some guidance. Thank you.