I need to use `\uline` (or something like it) from the `ulem` package for a custom command. Sometimes, when I use this custom command (in the mwe I just use `\uline`), I get a particularly dark, heavy (thick) underlining, compared with the standard.

For potentially relevant context: I'm using LaTeX, compiling with latexmk (via Vimtex), and viewing with Okular.

Why is this happening, and how can I stop it?

The effect is most noticeable with multiple paragraphs. Here it happens in the last line of the second paragraph:

```
\documentclass{article}

\usepackage{ulem}j

\begin{document}
\uline{Lorem ipsum dolor sit amet, consectetur adipiscing elit. Quisque laoreet lorem nec nulla sagittis, eu molestie lacus rutrum. Sed iaculis, est a faucibus rutrum, lacus lacus pellentesque magna, sed dignissim lorem arcu id est. Duis in convallis est. Duis gravida nisi quis turpis placerat, ut sagittis nunc tempus. Quisque pulvinar lectus nec orci scelerisque, id hendrerit metus tempor. Duis volutpat faucibus posuere. Ut semper turpis varius nibh ultrices luctus. Integer interdum urna vestibulum consectetur tempor. Nunc sed nibh tempus, aliquet erat non, ornare nibh.}

\uline{Donec viverra nec augue vitae commodo. Cras mollis ac sapien in pulvinar. Maecenas viverra ante a blandit tincidunt. Aliquam porta convallis lacus, sed mollis risus venenatis nec. Praesent eget tortor elit. Duis id ultrices lectus. Orci varius natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Maecenas sapien tellus, posuere ut lacus at, feugiat lobortis purus. Quisque condimentum magna in rutrum iaculis. Duis at justo quis nulla faucibus blandit vitae eu arcu.}

\uline{Donec fringilla vitae nibh nec sagittis. Sed bibendum dictum dolor sed vehicula. Nulla metus massa, sodales ut consectetur id, rhoncus at elit. Donec orci libero, ornare at mi at, congue mattis orci. Aenean laoreet lectus eget risus ornare porttitor. Morbi sagittis in velit et sagittis. Praesent eu hendrerit orci, faucibus iaculis massa. Nam magna lacus, tincidunt vel justo eu, aliquam mollis risus. Fusce facilisis, mauris in porta pellentesque, nisl augue commodo mi, pellentesque rhoncus nibh leo id risus. Aliquam erat volutpat. Vivamus at velit lacinia, mattis massa sed, molestie odio. Phasellus feugiat in elit vitae consectetur. Nullam ullamcorper quam sed vestibulum tempor. Vestibulum vel tempor magna.}
\end{document}

```

My initial examples included a `\renewcommand{\ULdepth}{1.6pt}` command (as it was par of my custom command) and in that case I could get the same effect with a single word (though it was less noticable. With the MWE above I can't. 

Any help appreciated, thanks!