Currently Leap 15.2 has deluge-gtk 1.3.15 and libtorrent-rasterbar 1.2.4 in the
repos.

deluge-gtk 1.5.x requires libtorrent-rasterbar 1.1.x.

We should downgrade libtorrent-rasterbar to the 15.1 version (1.1.7) or upgrade
deluge to the Tumbleweed version (2.0.3).

I favor the second option because deluge 1.3.15 is 3 years old and uses Python
2.7.

Note : deluge-gtk 2.0.3 from obs://build.opensuse.org/network is currently
lacking python3-service_identity as a dependency.

Source : https://forum.deluge-torrent.org/viewtopic.php?t=55535