The Output from swayidle -d should be similar to the following lines
2025-07-27 01:34:16 - [Line 1078] No config file found.
2025-07-27 01:34:16 - [Line 463] Using session: /org/freedesktop/login1/session/c4
2025-07-27 01:34:16 - [Line 1151] No command specified! Nothing to do, will exit
and the ouput from loginctl should list the session from the second line of the swayidle -d output.
SESSION UID USER SEAT TTY STATE IDLE SINCE
c4 1000 subm77 seat0 tty3 active no -
1 sessions listed.
If that is not the case you could look into setting up a login manager like greetd.
There is also river-classic and river 4.0 which has not yet been released.