Louder engine noise – Hyundai Elantra 2.0L 2019

I have an Elantra GT. After an oil change, I noticed the engine got louder. I used the right oil, not low or overfilled and used the right filter. Changing the oil doesn’t change. Under normal driving conditions, the engine is mostly quiet, but now in 2nd gear, (its an auto), it starts making a strained groaning at about 2000 rpm, and there’s some buzz in the gas pedal now. It’s weird because before, there was a lot of engine buzz about 2800 rpm, but thats mostly gone now. 2nd gear and above, the engine runs louder through out the RPMs, but If I accelerate slowly, it doesn’t make the groaning noise. I’m leaning towards the transmission. Could dirty fluids cause more noise? Or could it be something like high pressure.

Brand: Hyundai
Model: Elantra
Year: 2019
Engine: 2.0L