Loud hum when sampling with ubalanced cable

I get a loud hum when im sampling with an unbalanced cable on input 1.

Im wondering if every ISLA S2400 has this issue or of my version is flawed?

I have a trs cable that does this. I just use a regular aux 3.5 to 3.5 mm cable with the [6.3mm 1/4" Male plug to 3.5mm] jack and it works perfect no hiss at all for me

Thanks. Even if the source dosent have balanced outputs?