Is it possible that you could confirm the MCU that you are working on?
Please look at the image below, I am enabling the DMA using the FRDM-K64. If I select a preset option, the code preview shows how will be set up for this peripheral.
Oh I finally found "DMAMUX_Init()" here...
I thought it should be initialized inside "DMA_Init()", but it's not. It made me wonder for a while.
my bad here. thanks for your time anyway.