Cannot digitally sign my pdf document with my dsc pin, the blue okay button greys out

The Final Step of digitally signing my pdf in DC through certificates is a failure. I shifted to a Mac System and plugged in my dsc and probably installed the certificate in the system as well as i can recall. idk if it matters but i tried signing a pdf as i usually did in my windows laptop earlier and followed all steps where it let me choose the area and then the appearance of the signature and then when i finally try to type in the PIN of my DSC, (which is more than 8 characters) the blue ok button greys out and i am unable to type in my actual pin. it never happened in my windows laptop and i could type my PIN easily. I have tried with other documents as well. same issue repeated.