This is very interesting since this problem NEVER occurred to us before in the past 5 new cars that we owned (this 2018 Kicks SR is our 6th). So after turning off the car and closing the doors, when I go to lock with the fob, it doesn't lock nor make any sound nor show any indication that a signal went through. Somehow ONLY the button on the front drivers and passenger doors only unlock/lock. And another interesting part is that the fob battery isn't dead, since I didn't have to place it near the push-button ignition. So, any clue on what is causing this issue?

Sure sounds like a battery issue. The battery might be strong enough for the vehicle to recognoze the key once in the car, but not strong enough for the transmitter to emit a good signal. Either that or there is a problem with the fob itself. Do you have another fob to try so that you can rule out the vehicle itself?

I think its the fob, because unlike my Rogue's fob, this one has a light indicator on it, and when the car doesn't respond to it, I don't see a red light being emitted. I'm going to try the 2nd fob soon.

Sounds like this TSB. Key needs to be resynced.

https://static.nhtsa.gov/odi/tsbs/2019/ ... 9-9999.pdf