Headlights Turn off When Using Turn Signal?

Anyone encountered this, and what could be cause? Very intermittently, when I use turn signals while headlights are on (on auto setting and headlights "on" position) for example waiting to make a left turn, all the lights turn off. When I turn signal stock back to neutral position, lights work again. This has happened maybe 10 times over the past 5 years. Very weird. Anyone know why this is happening and how to fix? Thank you

 

What year is your truck?
Are you running stock halogen, 2018+ OEM LED upgrade, or aftermarket headlights?

 

I'd start my investigation with the switch itself.

 

it's a 2016 platinum, the headlight assembly is all stock, but I did replace the bulbs with Sylvania bulbs (ZTE I think?) when the OEMs burnt out. They are not LED bulbs.

 

Sounds like the switch is going bad.