Fill & Sign - Signature Issues

Hoping someone can help with this issue as I'm sure there's an easy fix but I just cannot sort it! 

For years I have used my actual signature to sign documents however I now cannot do that. When I click the button that used to have my signature I now only get an Adobe created version which I cannot use. I try and delete it but it refuses to disappear so I am just stuck with it. Having had a look I cannot find any settings to use my personal signature and on the odd occasion it does appear it will just revert back to the Adobe version the very next time.

Any pointers? TIA