Plasma 5 freezes on shutdown or restart

Noticed since I started using 42.1 with the KDE desktop, every now and then when shutting down or when restarting as instructed after an update, the desktop will semi-cloud over (best description I can think of!) and just hang.

It’s been happening for a long time, even on a new installation on my PC. I’ve just put up with it as a bug or whatever from Plasma 5.

Anyone else get this from time to time?

I’m quite new to linux and running Opensuse.

I think (but I cannot be sure) but this has happened on other Plasma 5 based distros for me.