Has anyone else experienced this issue in PTXprint? Do you know how to fix it?

Question

Hi everyone, does anyone know why this line 1-|a-|b2 is showing up in the printed output from PTXprint? It looks like a marker or a formatting code that wasn’t rendered correctly. How can I fix this?

https://drive.google.com/file/d/181i3YUQ2FVNoCdzsZe_WJ2ZC6PUNxqdY/view?usp=sharing