Three common symptoms, three different variables to test.

Use the visible result to decide what to change first.

Skipping

A broken line may come from too little ink, a dry nib or rough paper. Test ink loading before changing pressure.

If one side of a downstroke is rougher or darker, check whether the nib sits squarely and whether both tines contact the paper evenly.

If a word looks compressed, compare the white spaces between letters before widening the black strokes themselves.