Comment # 33 on bug 1047307 from Simon Herrmann

(In reply to Mikael Widersten from comment #32)
> (In reply to Simon Herrmann from comment #19)
> > > BTW, most likely the desktop was confused by the strange monitor layout
> > > (internal display having a different and even bigger resolution than the
> > > external one), made some unlucky/wrong assumptions and failed completely in
> > > the end.
> > 
> > I totally agree that the size got missunderstood by gnome or whatever piece
> > of software made that assumption about size. I don't know how to change
> > that, nor did I choose this size. Clearly, as correctly assumed by you, the
> > external monitor should be larger than the internal display, rather than
> > smaller as defined by default. By the way, am I the only one having this
> > problem? Does no one else use an external, second monitor?
> 
> I can confirm exactly the same issue. Thinkpad X1 4th gen Skylake 520
> graphics. Updated Tumbleweed. Plasma 5.10.3, Kernel 4.11.8. The problems
> started for me after June 16-ish. I have a Thinkvision display attached with
> a resolution of 1920x1200 dpi with a resolution on the hdpi laptop screen of
> 2560x1440. This has never (ever) caused any problem in the past. I have
> attached this laptop to numerous external displays and projectors of
> different resolution.
> 
> best,
> 
> /mikael

Thanks for sharing, good to hear that I'm not the only one not able to use an
external monitor :-)