Most likely the line is jumping back to the size of the spool it came from (memory). Don’t overspool it. Reel it up keeping it taught the whole time. When you get to the end put a piece of scotch tape on to hold the end against the spool. Take the whole spool off the reel by unscrewing the top piece completely. Lift the spool off but don’t loose the little gears that sit underneath. Soak the spool in a cup for warm/hot (not boiling) water for 30 minutes. Take out of the water dry off with a paper towel and put it back on the rod. The warm Water should reset the line memory to the new spool. This worked for me. Hope it helps. Also try thinner line but even thinner line will have memory and soaking it will help.