Help diagnose whirring or "womping" sound 2019 Tacoma TRD 4x4 sport

So, I'm hearing a cyclical whirring or humming noise coming from under my Tacoma - almost like when you saw through wood.

At first I 100% thought it was tire cupping because that is almost exactly what it sounds like. I visually inspected the tires and rotated them but the noise did not change at all.

The noise happens only between 10mph and around 25-30mph, both during acceleration and deceleration. During deceleration, the noise kicks in at the same moment the transmission downshifts. Almost like a "zing" sound. The noise raises in pitch and frequency when I accelerate and decreases in pitch and frequency when I decelerate.

When I decelerate I tried purposely shifting into neutral and the noise goes away, whereas if I left it in gear and allowed it to downshift, the noise would have been there.

this is leading me to believe the noise is in the transmission or driveshaft somewhere.

Below is a video link that I took from inside the cabin. If you listen past the cabin noise, you can hear a womp-woMP-WOMP low pitch under the truck.

For reference....
2019 tacoma trd sport double cab 4x4.
It has a 3 inch spacer lift in front with a diff drop kit. In the rear, I don't see any diff carrier drop kit. Planning to remove this lift as soon as possible. I bought the truck with the lift on, and an extended drivetrain warranty.

can you please give it a listen and let me know what you think?

https://youtube.com/shorts/38eoFXyy4R0?si=e77m9M9IW7wjZegL