Why is there no delay in my input signal after using fdesign.arbgrpdelay to introduce group delay?

I am trying to introduce frequency-dependent group delay using the arbitrary group delay filter "fdesign.arbgrpdelay" of the DSP System Toolbox in MATLAB R2021b. Although filter characteristics I get via "fvtool" look like I am designing what I intend, once the filter is applied it doesn't introduce any delay into the signal.

Why is no delay introduced to my input signal?

Answer 1

[MathWorks Support Team]

The input signal must be specified as a column vector instead of as a row vector. The number of rows of the input signal is the frame size, and the number of columns of the input signal is the number of channels.