Comment # 1 on bug 1087261 from Wolfgang Bauer

(In reply to Dario Savella from comment #0)
> The recent kernel upgrade from 4.4.114 to 4.4.120 introduced some regression
> ...
> I was able revert back to the previous kernel-default version and the
> problems disappeared.

Well, then it's rather a problem with the kernel update I would say, not
KDE/plasma (which wasn't changed anyway).

Btw, you are not supposed to change the Priority, that field is reserved for
the developers/maintainers to prioritize the bugs they are working on.
Only the "Severity" field is to be set by the reporter.
See https://bugzilla.suse.com/page.cgi?id=importance_matrix.html