I have had similar issues when I cleared the green stain with an acid bath before inking. I used to do this quite a lot, and then suddenly I started experienceing problems with ink adhering. It went away when I stopped using a weak acid bath before inking.
The only thing I could suggest is to change your fixer. There is a slim possibility that the problem you are experiencing is caused by residual fixer or acidity in the fixing bath. I'm not familiar with Agefix though.