Dear Maintainer, I can confirm that the backported patch posted by Timothy E. Harris fixes this problem in digikam 5.9.0-1.
It is a backport of the upstream fix https://commits.kde.org/digikam/b621054834cf955118bbd32c77d758128f744ee2 documented in upstream bug https://bugs.kde.org/show_bug.cgi?id=395875#c19 Thank you for your work. Regards, Peter Albrecht