Strange ends on my pencil lines

[defaultt8uyk2sgz3o2]

My question is about Illustrator. I like to use a pencil at 0% Fidelity (Accurate), 0.25 pt stroke/no fill to draw lines that look hand drawn. I then expand the lines. But I keep getting some proportion of lines that don't have a butt end, and instead have a sharp pointed end or a blob of anchor points. I need clean butt ends on my lines, so I then try to use the eraser on the messy ends of my expanded lines. Sometimes this leads to nice butt ends, but other times the line I drew gets completely changed and changes from a line to a sharp pointed shard. I did a test where I drew a series of lines with the characteristics listed above and used the Stroke Panel to change the end types (Butt, Round, Projecting) and the corner types (Mitre, Round, Bevel). No matter what Stroke attributes I chose, most of my lines had butt ends, but a small percentage had sharp pointed ends or blobby ends. Can you please help? Thank you

[defaultt8uyk2sgz3o2]

I am using the current version of Adobe Creative Cloud on a laptop Mac.

[Monika Gause]

Do you use effects?

Could this be your issue?

https://www.youtube.com/watch?v=624r93OTABo 

[Kurt Gold]

I'm pretty sure it just happens while drawing with the Pencil tool in (most) accurate mode. Usually, you may get then a couple of  adjacent anchor points that are located very close to each other and in conjunction with your settings in the Strokes palette some inevitable distortions may occur.

To inspect it further, you may want to provide a sample Illustrator file including the stroked paths you've drawn with the Pencil tool.