Hyundai Elantra not accelerating after put on D, but reverse works

Car: 2016 Hyundai Elantra, 1.8-liter four-cylinder engine, automatic transmission.

Issue: When I initially turn on the car and put it in D, it starts accelerating. But if I put it in R then back to D, the car stop accelerating. You can hear the engine rev when I press on the gas but it's as if the transmission doesn't kick in. I wait a minute or two then the transmission kicks in and I'm able to drive. I don't hear any weird noised from the transmission (at least from inside the car).

Attempts to solve the issue: I changed the transmission fluid on the car but still issue still happening. After some reading, I realized I need to have the car idling to confirm if the trans fluid is top off. I'll do that later today.

What is something else easy that I can do before taking it to a professional?