FFTA stops after executing thousands of iteration overnight

We are performing small fft using DMA in pipelined mode.

accel_cfft_small_pipe(fft_device, 1.0, n_points);

We are using 32 Byte aligned INPUT and OUTPUT buffer in SDRAM.

FFTA engine gets stuck after few iteration (N_POINTS 512 complex_float). Sometimes it executes 10000 iterations and sometime only 50 iterations.

When we run the same program for 256 complex N_POINTS, it is running smoothly for long durations lakhs of iteration tested.

What could be the reason behind this w.r.t. N_POINTS configuration.

Is there any memory limitation on FFTA for small pipelined FFT?

What all things are to be taken care while input/output buffer and FFTA's DMA config?