Created attachment 198269 [details]
The sddm-kcm uses /usr/share/xsessions and /usr/share/wayland-sessions pathes, but in FreeBSD the correct path is /usr/local/share/*.
This cause, that in sddm page of systemsettings, in the part of automatic login, the sessions are empty.
The quick patch fix this problem, and the other maybe good to the upstream. I tried both patch, works fine for me.
Created attachment 198270 [details]
maybe upstream patch
I agree, that looks upstreamable.
Closing, that Phabricator revision was committed upstream and it's been in a stable release since 5.15.0 (we currently have 5.15.1 in the ports tree).