Comment # 7 on bug 1119621 from Tejas Guruswamy

Testing further I do *not* experience the issue in IceWM or TWM. But again, I
*do* see it in tty1-6 console, sddm, and in plasma.
Even more weird, it gets noticeably worse (screen spends more time off) when my
laptop is on AC power and better when on battery. Some weird firmware/memory
corruption issue? But I don't think it is an actual hardware problem, as the
issue *never* occurs with 4.18.

Bill Wayson, David Rosky: I see complete screen blanking (not tearing), this
occurs for me with all 4.19 kernels, and occurs on the console as well, outside
of KDE/Plasma, so sounds like you both are describing something else.
David, note that xf86-video-intel is not recommended anymore (see earlier in
this bug for example), the system should be using the "modesetting" driver
instead. Works fine on my machine.
You could try installing
http://download.opensuse.org/history/20181112/tumbleweed/repo/oss/x86_64/kernel-default-4.18.15-1.2.x86_64.rpm
anyway to see if it helps. If it does not, I suggest opening a new bug.