How many input bus ? Why only 16

Hy guys.

I have a Mac with 30 physical inputs and a PC with 32 inputs Tascam DM4800 Firewire.
Both allow me to create only 16 input bus with Cubase AI… Is it normal ?
I read that the number of audio bus depends of the sound card so I could create 30/32 audio inputs …. I can’t !

Who has the answer?
Thank you

Cubase AI is limited to 16 physical inputs/outputs.

Thank you.