Also gotta keep in mind this is a major release. It’s allowed to break stuff, and the very first release is bound to have some bugs. We’re far into the Plasma 5 lifetime, a lot of the quirks have been ironed out.
It literally just came out, of course a lot of things haven’t been updated for it yet. Most people’s distros don’t even have it yet, addon authors don’t even know their addons are broken yet.