Thanks to the work of Emanoil, this has been fixed. See https://mirror.git.trinitydesktop.org/gitea/TDE/tdegraphics/issues/8 for the issue report and https://mirror.git.trinitydesktop.org/gitea/TDE/tdegraphics/pulls/54 for the fix.
Cheers Michele
(PS: sending from ML web interface, so no GPG signature attached)