On 15.5 totem says it cannot play DVDs:

"DVD source is required to play but is not installed"

and it offers to install additional software which then fails.

This is now installed:

libdvdcss2-1.4.3+3-lp155.10.1.x86_64
libdvdnav4-6.1.1-bp155.2.13.x86_64
libdvdread4-6.0.0-150000.3.2.1.x86_64
libtotem-plparser-mini18-3.26.6-150400.2.9.x86_64
libtotem-plparser18-3.26.6-150400.2.9.x86_64
totem-3.38.2-150400.2.12.x86_64
totem-lang-3.38.2-150400.2.12.noarch
totem-pl-parser-3.26.6-150400.2.9.x86_64
totem-pl-parser-lang-3.26.6-150400.2.9.noarch
totem-plugins-3.38.2-150400.2.12.x86_64
PackageKit-gstreamer-plugin-1.2.4-150400.3.6.1.x86_64
gstreamer-1.20-plugin-openh264-1.20.3-1.sle150500.2.x86_64
gstreamer-1.22.0-150500.3.2.3.x86_64
gstreamer-lang-1.22.0-150500.3.2.3.noarch
gstreamer-libnice-0.1.21-150500.1.1.x86_64
gstreamer-plugin-cluttergst3-3.0.27-150400.1.11.x86_64
gstreamer-plugin-pipewire-0.3.64-150500.1.2.x86_64
gstreamer-plugins-bad-1.22.0-lp155.2.8.x86_64
gstreamer-plugins-bad-lang-1.22.0-lp155.2.8.noarch
gstreamer-plugins-base-1.22.0-150500.3.3.1.x86_64
gstreamer-plugins-base-lang-1.22.0-150500.3.3.1.noarch
gstreamer-plugins-farstream-0.2.9+4-150400.1.12.x86_64
gstreamer-plugins-good-1.22.0-150500.4.3.1.x86_64
gstreamer-plugins-good-gtk-1.22.0-150500.4.3.1.x86_64
gstreamer-plugins-good-lang-1.22.0-150500.4.3.1.noarch
gstreamer-plugins-libav-1.22.0-bp155.1.5.x86_64
gstreamer-plugins-rs-0.10.1+git20230213.9cd68ff-150500.2.16.x86_64
gstreamer-plugins-ugly-1.22.0-150500.3.3.1.x86_64
gstreamer-plugins-ugly-lang-1.22.0-150500.3.3.1.noarch
gstreamer-utils-1.22.0-150500.3.2.3.x86_64
libgstreamer-1_0-0-1.22.0-150500.3.2.3.x86_64