Hello,
In my 2017 Accord LX-S, When I turn on the car and shift to D or S, the high beam lights turn on, even if the head light switch is on "OFF".
head light switch position breakdown for High beam (HB) and Low beam (LB):

OFF: HB: On, LB: OFF
ON: HB: On, LB: OFF
Auto (Day): HB: On, LB: OFF
Auto (Night):HB: OFF, LB: ON
Fixed: HB: OFF, LB: ON
Regardless of the Switch position, HB always turn on when the lever is pushed, Which is how it should work.
The above is true whether the car is on or off.

The LB and HB light bulbs are not OEM, Both are aftermarket LED Lights.
For the HB, I switched back to regular low-power Halogen bulbs to check, and the situations stayed the same.
What could be the problem? Can It be fixed?

 

When car is turned on, the DRLs will turn on. DRLs are ths high beam powered up to 60% to 70% power. This is done thru pulse width modulation. The more time the signal is high then the more power to the DRLs. Turn on the low beams and the system thinks you are driving at night and will turn off the DRLs.