\ul from the soul package eats last character if it has less common diacritics

Question

I am using the soul package to underline text, since it allows me to select at which height to place the underline.

However, for some reason if the last underlined character has a less common diacritic (perhaps those which LaTeX cannot combine with a command like \'a or \~a?), such as the macron or breve below, it simply removes this character. If there are multiple characters like this at the end, it removes all of them.

This does not happen if the character appears anywhere else in the text, as long as it is not at the end of the string.

I came up with a hack, where I enter the last character as if it had no diacritic, and add the diacritic after the \ul ends. This happens quite often though and is very annoying as well as not very readable in code.

Is there a way to fix this behaviour so that I can use \ul with these symbols?

See below:

\documentclass{article}
\usepackage{soul}
\begin{document}
    \noindent
    \ul{paḫ}ša (should be paḫša)    \
    \ul{mā}ter (should be māter)    \
    \ul{māā}ter: multiple letters disappear (should be māāter)  \
    \ul{māa}ter \  % no problems here
    \ul{má}ter  \  % no problems here
    \ul{mã}ter  \  % no problems here
\noindent
\ul{pah}\symbol{"032E}ša    \\
\ul{ma}\symbol{"0304}ter    \\

\end{document}