Where is the TPMS wireless relay?

Does anyone know where the TPMS relay is mounted.
My back left wheel doesnt always show up with the monitor on the dash. And the right middle one drops.
Today while in the trailer it worked fine.

I am guessing the relay is too far from the wheels. The manual wants the relay closer to the tires.

On my 2900, it’s mounted on the underbelly in the middle of the trailer. Mines yellow and has a little indicator light.

On the G it is mounted on the underside as well, just forward of the axles.