Most fixed spools only work well with a limited variety of line diameters. Stray outside of that and the line lay is compromised. Is the line diameter correct for the spool? Is the spool the correct one for the reel and not from the next model up?
Some reels have spools that have various location notches in their base. These can be used to fine tune the spool height on the spindle in relation to the bailarm roller and line diameter used. Some come with washers that can be placed or removed from the inner base of the spool to do the same fine tuning. Some people will hand wind on the first layers of line to profile the spool for the top useable layers. This used to be a regular thing to do before the introduction of the long tapered spools. Some of the shorter spools still need it.
You say the line appears to be stopping short at the top and bottom of the spool? That sounds like it's the wrong spool. What diameter of line are you using on it as thicker will / should cure it. The problem being it could be too thick for what you want to use.
Sean -
PS - That's what you get for using a mangle!
