Nib Fountain
How do you clean with fountain pen?
I have a fountain pen Cross Underground has not worked well since I bought it. It tends to jump after use for more than 20 minutes. I run under hot water, but I loose ink that way.
Try dipping it in alcohol. That should dissolve dried ink that may be causing a jump. I am surprised that you have problems with it, because the products are generally of high quality Cross.