I installed adobe dc standard on a second computer for another user. I have created a second digital signature but can only sign with my signature. If I look at the preferences and signatures the second one appears but when they go to fill and sign only my signature is available.
Can you provide a few screenshots of what you are seeing? For example:
1) Screenshot of preferences -> signatures where you see the second signature.
2) Screenshot of Signature dialog where you only see your signature as available for signing.
Also, what steps did you use to create second signature?