Hello sero,
Welcome to our forum and thanks for contacting us with your question!
Could you try to reproduce your chart in a form of a live working demo? It is hard to tell without looking at the code what is the cause of such shapes. You can start here:
https://jsfiddle.net/BlackLabel/kt6q043f/
Also, you don't need to include all the 14,000 points, just add few of them as a sample data.
Best regards!