Comment # 10 on bug 997294 from Wolfgang Bauer

(In reply to Vladyslav Hnatiuk from comment #9)
> With "nomodeset" parameter system starts good, but resolution is 1280x720
> and I can't change it.

So it does seem to be related to the graphics driver somehow.
Though it's probably unlikely that both radeon and intel would have the same
"bug" that causes such a problem.

OTOH, it does not happen with the fallback driver (likely fbdev), so it's not
really a general problem in sddm either.

Assigning to Xorg for now, maybe they have a clue how to investigate further.
Feel free to re-assign.

Btw, you didn't answer this one yet: does it also happen with IceWM, or only
Plasma5?