Dear Maintainer,

kile: The inverse search with external browser "okular" only works if the
editor in "okular" is configured  as "custom editor" with the command line
"kile --new --line %l %f". This opens a new instance of "kile" pointing to the
correct location in the source file. So, in the new instance, the inverse
search works correctly.
Without the "--new" option, nothing happens.

ChatGPT provides the following analysis:
The symptom (“works only with --new, otherwise nothing happens”) points to a
single-instance / D-Bus arg-forwarding bug in this Kile build. Okular is
sending %f and %l fine (since Kate/Emacs work); Kile just isn’t applying --line
to an already-running window.