Hi,
Did you try to start the DMA channel via overlay.axi_dma_0.sendchannel.start() [or dma.sendchannel.start() ] ?
Why did you comment the wait functions?
Did you check Running FFT with axi dma channel wait “DMA channel not started”?
You can obtain indications via help(overlay.axi_dma_0.sendchannel) or help(overlay.axi_dma_0) for example.
Sincerely