CMSIS Matrix inverse returns singular for nonsingular matrices

Hi

I have been testing the CMSIS DSP matrix inverse function and am observing unexpected results. In particular, the function arm_mat_inverse_f32 returns ARM_MATH_SINGULAR for matrices that are clearly not singular. For example, a 4x4 identity matrix (ones on the diagonal, zero everywhere else) returns a singularity error.

Is this expected behaviour? Is there a way to improve this?

Thanks!

Markus