A wire is frayed/ burned/ loose. There is no connection, besides being on the same car between DRL and turn signal on a 2007 model. The left headlight and the turn signals do ground at the same point on the left shock tower.

On 2006 models the turn signals serve as DRL.

The different front and rear bulbs is really only important on 2006 models to avoid melting plastic.

 

I’m my 2007 LS , I slways left my headlights on auto. No issues, the signals always worked. I’m thinking your issue is the bulb socket on the driver side front.

As we see in this Amazon ad, the socket is separate from the wire harness

ACDelco 12335899 GM Original Equipment Turn Signal and Parking Lamp Socket https://a.co/d/ajpeoKS