Are you talking about the keyfob? If so, then one press=driver's door unlock. Double press=all door unlock. No issue, this is how it was made to perform.

If you are talking about the unlock button on the door, then yes, you have an issue. Pressing the unlock on the door should unlock all the doors.

 

i'm having the same issue here in Malaysia.. looks like it's just bad contacts..

 

I sometimes have to press the button two or three times, but I figure it's just age.

 

Best way out would be to go to breakers and get a used complete switch unit

 

I think there is a way to configure the car to unlock all the doors when the car is put into park. You would need to check your manual to see if your year car has that feature.

I found this in the manual for a 2009 Sonata:

Auto door lock/unlock feature​

(If Installed)​

o All doors will be automatically locked​

when shifting the transaxle shift lever​

out of P(Park).​

o All doors will be automatically unlocked​

when shifting the transaxle shift lever​

into P(Park).​

NOTE:​

An authorized Hyundai dealer can activate​

or deactivate the auto door lock/​

unlock features.​

If you want to activate or deactivate the​

auto door lock/unlock features, consult​

an authorized Hyundai dealer.