Why are lines showing on my sparkline that are above the max?

I have this Google sheet, using sparklines to graph a change over time. I want a horizontal line at 2 different points, which cannot be done with a sparkline. So as a workaround, I have 3 different sparklines covering the same data but with different mins and maxes so I can draw a border between them.

But there are 6 parts (encircled in red) where lines are showing on the sparkline where they should not be.

What am I doing wrong?

https://docs.google.com/spreadsheets/d/1paFqu2hWAlpnzc3Ba0uo2kBfy9Inf2X6iWjQTzr_6XE/edit?usp=sharing