[Bug] Some parentheses are not visible in the html export but are present

[Niall Dooley]

Some parentheses are not visible in the html export but are present.  This
was not always the case with the provided example.

--- Begin Example ---
* islower()
** Front
*String method* that returns =True= if the string is a lowercase string, =False=
 otherwise.
** Back
*String method:* islower(self, /) -> bool
** Usage
#+name: str.islower()
#+begin_src python
<astring>.islower()
#+end_src
** Remarks
A string is lowercase if all /cased/ characters in the string are lowercase and
there is at least one cased character in the string.
--- End Example

The parentheses under the Back subheading are displayed in the export.
However, the parentheses within the src block under the Usage headline are not
visible but are nonetheless present.  This can be seen by highlighting the
region in the exported html file.  If I add some text within these parentheses
the text is visible on export but the parentheses are still not.

Org mode version 9.7-pre (release_9.6.8-740-gdeb5ea @
/home/doolio/.emacs.d/straight/build/org/)
GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.24,
cairo version 1.16.0) of 2023-02-23, modified by Debian