Hmmm okay then you must have created your local builds in a different way, because people reported this problem since early May in Preview Iso Topic, but nobody was helping them:
With your latest FULL KDE ISO. After logging inside TTY3 TTY4 TTY5 TTY6 (with manjaro/manjaro) i relentless switched to TTY2 and login (login/pw) to experience blackscreens. But after another time TTY6 (where i was already logged in) i swapped to TTY2 (login screen) and gave in PW… i probably repeated it at least 2-3 times.
You have to do this logins relentless, but i could repeat this logins for 5 times now… but it took me around 3-4min for a finally desktop login.
Since im a gamer, i created a little high score… i could manage to loggin one time in just 2min, there might be a hidden combo required 